Castration of protected Sanyo and Panasonic batteries and a small educational program on Li-ion. Castration of protected Sanyo and Panasonic batteries and a small educational program on Li-ion Marking the capacity of 18650 batteries

18650 has become increasingly popular lately. In terms of their technical characteristics, they are ahead of the well-known AA batteries. The concepts of “finger” and “little finger”, used for well-known ones, from the point of view of correct terminology, are incorrect. All batteries, regardless of size, have their own codes indicating their size. So, 18650 is also a code. That's the whole secret.

Battery size 18650

This five-digit code expresses the width and length of the battery, where the first two digits are the width (diameter) in mm, and the last three are the length in mm with tenths. There is a misconception that the zero at the end of this code indicates the cylindrical shape of the battery (there are batteries of different shapes). Such an exact designation of the battery length is not necessary. When specifying its size, it is often limited to the first four digits (1865). By the way, finger and little finger batteries also have their own code - 14500 and 10440. In addition to the digital code, the size can also be indicated by letters. For example, the two above-mentioned battery sizes have alternative letter codes - AA (finger) and AAA (little finger). There are many letter and number codes indicating the sizes of different batteries: CR123 (16340), A (17500), Fat A (18500), 4/3 A (17670), etc.

For 18650 batteries, this size designation is not accurate. Other parameters need to be taken into account. The size of the 18650 battery can be influenced, for example, by the presence of a built-in special board (charge controller). Some batteries may have a slightly longer length in this case. There are often cases when the battery simply does not fit into the compartment of the device where they want to use it, despite the fact that this device (for example, the battery pack of an electronic cigarette) is designed to work specifically with batteries of this type.

18650 Li-ion Battery Lifetime

The time that a given battery can work depends on such a concept as “milliamps per hour” (mAh). For large batteries, such as car batteries, the term "amps per hour" is used. For a 18650 mAh battery this is a derived value. One amp is equal to 1000 milliamps. Milliamps per hour is the current that a battery can produce during a conventional hour of use. In other words, if you divide this value by a certain number of hours, you can find out the operating time of the battery. For example, the battery has a capacity of 3000 mAh. This means that for two hours of operation it will produce 1500 milliamps. For four - 750. The battery from the above example will be completely discharged after 10 hours of operation, when its capacity reaches 300 milliamps (deep discharge limit).

Such calculations only give an approximate idea of ​​battery life. Its actual operating time depends on the load it has to deal with, that is, the device it must provide power to.

Current, voltage and power

Before dwelling on a general description of the technical characteristics of 18650 lithium-ion batteries and precautions when working with them, we will briefly define the above concepts. Current (maximum discharge current, current output) is expressed in amperes and is marked on the battery with the letter “A”. Voltage is expressed in volts and is symbolized by the letter “V”. You can find such designations on many batteries. For a lithium-ion battery, the voltage is always 3.7 volts, but the current can vary. The power of a battery, as the main parameter of its strength, is expressed by the product of voltage and current (volts must be multiplied by amperes).

Description of the pros and cons of a lithium-ion battery

The main disadvantage of 18650 size batteries produced using lithium-ion technology is that they have a small operating temperature range. Normal operation of a lithium-ion battery is only possible within the range of -20 to +20 degrees Celsius. If it is used or charged at temperatures lower or higher than those indicated, this will damage it. In comparison, nickel-cadmium and nickel-metal hydride batteries have a wider temperature range - from -40 to +40. But, unlike the latter, lithium-ion batteries have a higher nominal voltage - 3.7 volts versus 1.2 volts for nickel batteries.

Also, lithium-ion batteries are practically not susceptible to the self-discharge and memory effects common among many types of batteries. Self-discharge is the loss of charged energy during idle time. The memory effect occurs in some types of batteries as a result of systematic charging after incomplete discharge. That is, it develops on batteries that are not completely drained.

With the memory effect, the battery “remembers” the degree of discharge after which it begins to be charged, and discharges, reaching this limit in the next cycle. Its true capacity at that time is actually greater. If there is a display board, it will also show the discharge. This effect does not develop immediately, but gradually. It can also develop in conditions where the battery is constantly operating from the electrical network, that is, it is continuously charging.

Self-discharge and memory effect are extremely insignificant in lithium-ion batteries.

There is one more point that you should pay attention to: such batteries cannot be stored in a discharged state, otherwise they will quickly fail.

Precautions when working with a lithium-ion battery

Many are susceptible to fire and explosions. This depends on the chemical composition of the internal structure of the battery. For lithium-ion batteries of size 18650, this problem is quite acute. It is not uncommon for e-cigarette users to suffer serious burns on their hands and face, or even more serious injuries. Since lithium-ion batteries are found in laptops, tablets and cell phones, it is not uncommon for them to catch fire.

In first place among the reasons for such incidents is, of course, poor-quality (cheap) battery assembly. However, in the case of electronic cigarettes, an explosion of a lithium-ion battery is easy to provoke on your own, even if the battery is not cheap. To do this, you need to understand a little about what electrical resistance is.

If we explain this concept in the simplest language, then this is a parameter that determines the requirements of the conductor for the battery. The lower the conductor resistance, the more current (amps) the battery must deliver. If the resistance is very low, then the battery will work with such a conductor under a large load. The resistance can be so low that it will cause an excessive load on the battery and its subsequent explosion or ignition. In other words, it will be a short circuit. Since e-cigarettes operate on the principle of vaporization, which requires a heating element (incandescent coil), inexperienced users may mistakenly force the battery to operate with a heating element with extremely low resistance. Knowing the current output of a particular battery and the resistance of the conductor, using simple calculations using the Ohm's law formula, you can determine whether a given battery can handle a particular conductor.

These dangerous phenomena do not always occur and not in all cases. Battery protection technologies are constantly being improved. Many batteries have a special charge controller inside that can cut off power to the battery in time if a short circuit occurs. These are protected batteries.

Lithium-ion battery device

The 18650 battery is based on an electrolyte - a special liquid in which chemical reactions occur.

These chemical reactions are reversible. The principle of operation of any battery is based on this. In simple terms, the formula for such reactions can proceed both from left to right (discharge) and from right to left (charge). Such reactions occur between the cathode and anode of the cell. The cathode is the negative electrode (minus), the anode is the positive electrode (plus) of the power source. An electric current is formed between them at the moment of reaction. The chemical reactions of discharge and charge between the cathode and anode are processes of oxidation and reduction, but that is a completely different story. We will not delve into the electrolysis process. Current is generated at the moment when the cathode and anode begin to interact, that is, something is connected to the plus and minus of the battery. The cathode and anode must be electrically conductive.

When operating conditions are violated, molecules of chemical elements appear in the electrolyte, which short-circuit the cathode and anode, which leads to internal short circuits. As a result, the temperature of the battery increases and more molecules appear that close the plus and minus. This whole process, like a snowball, gains exponential speed. Without the possibility of removing the electrolyte to the outside (the battery case is sealed), increasing internal pressure occurs. What happens next can be understood without comment.

Charging the lithium-ion battery

Any device designed for batteries of this format is suitable as a charger for the 18650 battery. The main thing is not to change the correct polarity when charging. The batteries must be placed in the slots exactly in accordance with the plus and minus markings. It would be a good idea to familiarize yourself with other precautions when using a charger for an 18650 battery, which are always indicated on its case.

The best option for charging lithium-ion batteries is to use more expensive chargers with fine tuning of the charging process. Many of them have the function of charging batteries using the CC/CV method, which stands for constant current, constant voltage. This method is good because it can charge the battery more than conventional chargers do. This is connected with such a concept as recharge.

As the battery charges or discharges, its voltage changes. When charging it increases, when discharging it decreases. The nominal 3.7 volts is an average value.

There are two effects that have a detrimental effect on the battery - overcharging and overdischarging. There are thresholds for charging and discharging the battery. If the battery voltage goes beyond these limits, the battery is overcharged or overdischarged, depending on whether it is being charged or discharged. In normal charging mode for 18650 Li-ion, the charger and charge controller inside the battery itself (if there is one) reads the battery voltage and cuts off the charge when a threshold is reached to avoid overcharging. However, the battery is not actually fully charged. Its capacity may allow it to charge more, but the threshold value prevents it from doing so.

The principle of charging using the CC/CV method is designed in such a way that the current supplied to the charge is not cut off, but is sharply reduced, preventing the internal voltage of the battery from going beyond the threshold value. Thus, the battery is fully charged without overcharging.

Types of lithium-ion batteries

Types of 18650 Li-ion batteries:

• lithium iron phosphate (LFP);
• lithium manganese (IMR);
• lithium cobalt (ICR);
• lithium polymer (LiPo).

All types, except the last one, are cylindrical in shape and can be made in the 18650 format. Lithium polymer batteries are different in that they do not have a specific shape. This is due to the fact that they have a solid electrolyte (polymer). It is due to this unusual property of the electrolyte that these batteries are often used in tablets and cell phones.

Applications of lithium-ion batteries

As already mentioned, 18650 size lithium-ion batteries are widely used in e-cigarettes. They can be built into the battery pack or removable, that is, installed separately in it. There can also be several of them, connected in parallel or in series.

Lithium-ion batteries have long been used in various batteries, such as laptop batteries. Such batteries are a chain of several interconnected 18650 batteries inside a single housing. Such batteries can also be found as capacious power banks - portable chargers.

The scope of application of the batteries themselves is very wide: from the named chargers to the constituent elements of modern large mechanisms (automobile or aircraft). Moreover, the number of 18650 lithium-ion batteries that make up a single battery can vary from a few pieces to hundreds. It is worth mentioning lithium polymer batteries. Although they are not available in the 18650 Li-ion format, they are the most common, as they are used in tablets and cell phones.

To answer the question of what the 18650 format battery is used for or what it is also called - 168A, let's study its characteristics and capabilities, as well as examples of use in domestic conditions.

This type of battery is currently quite popular for a number of reasons, but the main ones are the voltage of 3.7-4.3 volts and good capacity (running time) up to 3600 mAh, as well as a fairly compact size.

They are similar in shape to AA-sized “finger” batteries and AAA-sized “pinky” batteries, but larger in size. As mentioned above, the output voltage of these batteries is 3.7 - 4.3V. Capacity is 2200-3400 mAh.

AA and AAA AA batteries have a voltage of 1.5V

At Ni-MH ( nickel-metal hydride) batteries of AA and AAA format - 1.2V.

Schematic device of a Li-ion battery

Li-ion battery capacity 18650

Energy capacity is the amount of energy that is stored in the battery. Battery capacity is often expressed in watt-hours (Wh), kilowatt-hours (kWh) or ampere-hours (Ah). The most common measure of battery capacity is Ah, defined as the number of hours that the battery can supply a current equal to the discharge rate at the battery's rated voltage. A watt hour is the voltage (V) that the battery provides multiplied by the amount of current (amps) the battery can provide for some time (usually in hours). Voltage*Ampere*hours = Wh. Since the voltage is highly dependent on the battery type due to its internal chemistry (alkaline, lithium, lead acid, etc.), often the battery side only displays amp hour data expressed in Ah or mAh (1000 mAh = 1 Ah). To get Wh, multiply Ah by the rated voltage. For example, suppose we have a nominal 3 V battery with a capacity of 1 Ah or 1000 mA*h, its power will be 3 W.

1 A*h means that theoretically we can use 1 ampere of current for one hour or 0.1A for 10 hours or 0.01A (10 mA) for 100 hours.

IMPORTANT! At the time of writing, there are NO batteries with a capacity higher than 3600 mAh in the 18650 size!!!

Battery size 18650

Decoding the digital designations of the 18650 battery:

the first two digits (18) – diameter;

the next pair of numbers (65) is the length;

the last digit (0) indicates the shape of the battery, in this case a cylinder.

As we can see after measurements, the length of the cheapest Chinese battery brand UltraFire (manufacturer of cheap Chinese flashlights) 18650 format is 66.5mm, and the diameter is 18mm.

Let's compare the sizes with other types of batteries:

AAA: 44.5 x 10.5 mm

AA: 50.5 x 14.5 mm

14500: 53 x 14.5 mm

18650: 65.5 x 18 mm (unprotected)

18650: 67.5 x 18 mm (protected)

26650: 67.5 x 26.1 mm

A visual comparison of AA, AAA and 18650 batteries.

And although the 18650 format battery resembles finger and little finger batteries, it will be larger in size.

What is a protected battery

18650 batteries come with and without protection - if the 18650 battery does not have protection, then there are no additional inscriptions on it, or the inscription “Unprotected” is present. The length of the unprotected one (without a protection board against complete discharge or overcharge) is 66.5 mm.

If the battery description contains the words “With Re/Discharging Protection Circuit” (protection from complete discharge/overcharge), “Protected”, “With protective PCB”, “Protection Circuit”, etc., then the battery has a protection board on board. A small thickening (usually a 1mm plate) near the contact is the battery protection board.

For reliable operation and to avoid damage, complete discharge or overcharging and overheating, Li-Ion batteries must operate within a voltage range of 4.2-2.5V.

One of the weak points of Li-ion batteries is that they are subject to failure during overcharging and/or overheating, as well as when they are completely discharged. After which it will be problematic to restore or charge the battery or it will lose its initial capacity. If handled carelessly, lithium-ion batteries can fail more often than other types of batteries.

This problem is solved, as noted above, by installing an electronic protection circuit that prevents excessive overcharging and/or overheating as a result of exceeding the permissible current during charging, and also interrupts the circuit when the charge is low, protecting the battery from deep discharge during operation. This protection board not only ensures that the battery operates within the safe voltage range, but also prevents overcurrent and short circuits. The protection board is spot welded using a steel conductor to the corresponding battery contacts. In reality, it looks like this: an electronic protection board with a thickness of 1-3mm and the diameter of the battery is installed on the negative contact of an unprotected Li-Ion battery (“cell”).

The length of such a battery is slightly longer - on average 67.5-70mm versus 65-66mm for an unprotected one. When the battery voltage rises above 4.25V, the protection board blocks further charging of the battery to prevent it from being damaged by overcharging and overheating. The same thing happens when the voltage is less than 2.75V - the protection board blocks further discharge of the battery below the specified threshold.

Typically, large Li-Ion battery manufacturers do not produce batteries with built-in protection. They only produce unprotected batteries. As a rule, there are no protected Li-Ion batteries of the SAMSUNG or Panasonic brand, which would be released specifically by “Panasonic in Japan” or “Samsung in Korea”, and those who prove the opposite are intentionally or unintentionally trying to mislead you misleading.

Protected batteries are assembled from conventional Li-Ion batteries (cells) followed by installation of a protection board.

The assembly process can occur in different ways: as a rule, the battery assembly with protection is carried out at enterprises in China. But China is different - there are both outright counterfeits and amateurism on the part of little-known battery manufacturers (with imaginary capacities from 3800 mAh to infinity) and very high-quality products from well-known brands.

Protected batteries are assembled and sold by completely different brands that are not related to the manufacturer of the batteries themselves. A factory-assembled battery with protection is covered with a thermal shell with the brand name and an indication of the capacity (sometimes real and sometimes absolutely fantastic).

Due to the fact that a protected 18650 battery is 1-3 millimeters longer than its unprotected counterparts and sometimes 0.5 mm thicker in diameter.

Extended batteries with protection may have a standard size of 18700, and size always matters - such a battery may not fit into the battery compartment of some consumer devices. Therefore, when choosing a protected battery, you should think about whether it is the right length, for example, for your LED flashlight, charger, etc.

Mechanical - internal protection of Li-ion batteries

In addition to protection using a charge controller board, the battery can use an internal mechanical protection system for the battery. The internal protection function is to trigger a special mechanical switch as a result of the temperature threshold (overcharge/heating) and pressure inside the battery increasing to critical values, which can lead to an explosion. The battery is disconnected by mechanically breaking the circuit by the internal protection of the power source. If this does not help and the temperature and pressure continue to rise further, then the pressure relief valve is activated, which releases gases and electrolyte outside.

The mechanical switch itself is quite common as a primary or additional safety measure in many batteries, functioning in conjunction with or without a charge controller (board). It is worth noting that the presence of internal protection will not necessarily be mentioned on the case or in the description of the technical characteristics of the product. As a rule, well-known manufacturing companies will not neglect the internal mechanical protection of their power supplies with an unstable chemical composition, with the possible exception of the cheapest and little-known Chinese brands. Therefore, regardless of whether any power supply has or does not have an electronic protection board, it must have built-in physical protection.

Use of protected and unprotected Li-ion batteries

18650 batteries are usually used where long battery life is required in a compact size.

Both unprotected and protected batteries can be used in any devices or devices designed to work with Li-Ion power sources, the only difference is that if the device or device do not have a built-in charge-discharge controller, then this disadvantage can be compensated for by a protected power supply.

The main devices that use Li-Ion batteries today are LED flashlights and lamps, since these batteries have sufficient power and capacity to ensure long-term and uninterrupted operation of the latest generation of powerful LEDs in these devices.

In our particular example, these are LED lights with diodes of the latest generations XM-L/L2, XP-L/L2, etc. (Convoy s2+, Convoy c8).

This flashlight contains AAA battery

This flashlight runs on AA battery

And these lights are equipped with the latest generations of LEDs CREE XM-L2, XP-L2. They require a lot of power to operate. That is why these flashlights are powered by an 18650 battery and are made for it, as it is ideal for these purposes.

Some flashlights from cheap Chinese brands such as UltraFire are designed in such a way that the 18650 battery can be replaced with 3 AA batteries through a special adapter. In this case, the voltage is almost the same: 3.7V and 4.5V (= 1.25V*3 or 1.5V*3).

In most cases, for simple Chinese LED flashlights such as UltraFire, a protected battery is required.

It happens that some batteries have too sensitive current protection and operate at less than permissible values. In this regard, flashlights using powerful LEDs of the latest generations XM-L/L2, XP-L/L2 do not function properly. When you turn on the flashlight, an overcurrent occurs - the battery protection is triggered, the flashlight may blink and no longer show signs of life. If you change the battery to an identical one, the same thing can happen; the protection is triggered instantly. There are two options - either remove the protection board and use the battery without it, or replace the battery with another one from a time-tested brand.

As mentioned above, battery protection definitely increases the length of the battery by 1-2 mm, or even more. If the Li-Ion battery with protection reaches a length of 7 cm, for some compact flashlights designed to install a Li-Ion battery it is impossible to screw the back cover and you have to look for the battery without protection or remove it again. The longer the battery, the greater the force of the springs on it in the battery compartment; it happens that they push through the negative contact of the Li-Ion battery. Most often this happens when the flashlight is used as an under-barrel flashlight during recoil during a shot. And it’s not very pleasant to push such a battery into the battery compartment of the flashlight by forcefully twisting the lid, scratching and damaging the battery contact with the spring.
But no matter what the battery protection is, it does not 100% guarantee the safety of the battery and flashlight from overheating and even explosion.

Usually, the increased pressure in the battery is released through special holes in the battery valve, but in the sealed space of the flashlight they may not help.

In principle, if you know the approximate effective operating time of a Li-Ion battery based on its capacity in a particular consumer, then you can safely use unprotected batteries. Many people do this. This applies to flashlights with a single battery. If several batteries are used, protection must be required.

It happens that the protection board fails. To restore further use of the battery without it, do the following:

Remove the polymer coating (shell);

On the case you can see the positive conductor going to the protection board, which is simultaneously spot welded to the battery case (minus). In case of critical current and voltage values, the protection board breaks this circuit;

The protection board is removed, freeing from spot welding. Remove the conductor;

Remove the sheath around the negative terminal so that the contact is accessible for connection to the final consumer devices;

Instead of the original shell, you can use ordinary adhesive tape or electrical tape or self-adhesive film of any color, cutting a piece out of it to the size of the battery and carefully covering it with it. With such a film, the battery will become unique, especially if you wrap it in carbon film. :-)

After removing the protection board, the battery will lose 1-3 mm in length. And it will become an ordinary battery without protection.

If, for example, you need to repair the battery in a laptop, upgrade the battery in a screwdriver, or you need a prefabricated BATTERY from Li-Ion batteries, then for this you need to use unprotected batteries.

Pros and cons of lithium-ion batteries

Typically a 18650 battery is li-ion-th battery.

The main advantages of Li-ion batteries are:

High energy density;

Higher voltage (compared to NiCd and NiMH batteries);

Low self-discharge 4–6% per month, 10–20% per year;

No “memory effect”, no need for “training” after purchase - there is no need to fully charge and then completely discharge lithium batteries after purchase;

Wide operating temperature range – from -20 to + 50 °C;

Long service life of about 10 years;

Significant reserve of discharge-charge operating cycles of more than 1000;

Ease of maintenance;

Low specific gravity.

A few disadvantages of Li-ion batteries:

Relatively expensive (every day this minus disappears);

Low resistance to overcharge and complete discharge, which is why smart Li-Ion batteries are equipped with built-in automatic shutdown systems;

Unlimited range of operating temperatures (from -20 to + 50 C), deterioration of performance at high temperatures, reduction in capacity when used in cold weather;

Difficulty charging at low temperatures;

Explosion hazard if the housing is damaged, punctured or otherwise sealed;

Dependence of service life on time, and not on the number of discharge and charge cycles, over time there is a gradual loss of capacity

Storing lithium polymer and lithium ion batteries

Lithium polymer and lithium ion batteries lose capacity when charged, unlike nickel and nickel metal hydride batteries. The higher the battery charge and the temperature during its storage, the shorter its service life. Overcharging, like overdischarging, “burns out” the battery capacity.

The optimal storage conditions for Li-ion batteries are:

• 40-50% charge of battery capacity;
• temperature 0-10 degrees Celsius.

At the same time, low temperature is a more important factor for small losses of capacity during long-term storage. The average shelf life (service) of a lithium battery is on average 36 months. Lithium batteries age even when not used.
(Wikipedia).

To extend the life of your lithium battery and improve its performance, you need to follow simple recommendations:

Avoid completely discharging the battery, recharge it regularly when the charge level drops to 20%;

do not allow the battery to overheat or expose it to direct sunlight;

Do not use the battery in severe frost; insulate it for use in winter;

store the lithium-ion battery with a 50% charge level, at a temperature of 0 C;

protect the battery from shock, damage and strong vibration; when installing it on electric vehicles, use a soft layer

Deciphering markings and inscriptions on batteries

In mass production, three classes of Li-ion batteries are used (based on the cathode material, the second letter in the marking):
1) lithium-cobalt LiCoO2 (the most common, the highest capacity among Li-Ion)
2) lithium-manganese LiMnO2, LiMn2O4, LiNiMnCoO2 (better known as high-current (INR), capable of delivering currents of 5-7C to the load, which are usually inferior in capacity to the former)
3) lithium ferrophosphate LiFePO4 (excellent batteries undervalued by the market, in all respects they undoubtedly outperform the first two types, except for operating voltage and capacity, it is even lower than that of INR)
As they say, all three classes are tailored to perform specific tasks and have their pros and cons.

Since there are no uniform battery labeling standards, all manufacturers label them differently. But ideally it should be something like this:
1) the first letter is the manufacturing technology (I - lithium-ion technology)
2) second letter - type of chemistry, cathode material (C/M/F - cobalt/manganese/iron phosphate chemistry)
3) third letter R - battery (rechargeable)
4) five digits - form factor (the first two digits are diameter, the next two are length, the last digit is the shape of the acca (0 - cylindrical))
- 10440 (everyone’s familiar “little fingers”)
- 14500 (everyone’s familiar “fingers”),
- 16340 (size like a CR123 battery),
- 17335 (not common)
- 18500 (also not very common)
- 18650 (the most common form factor on the market),
- 18700 (unofficially, 18650 battery + protection board, i.e. protected battery),
- 26650 (enlarged, came to the market from the company A123 Systems, which produces lithium ferrophosphate batteries)
- 32650 (absolutely monsters, only for stationary devices, weight almost 150g)
- plus unofficial f/f with protection boards, for example 18670...
5) letters/numbers - specific marking of the container (different for all manufacturers)

An example of marking, but as a rule, it is different for all manufacturers:
- Samsung ICR18650-26F (lithium-ion battery with the usual cobalt chemistry, f/f 18650 with a capacity of 2600mah)
- Samsung INR18650-20R (lithium-ion battery with manganese chemistry, i.e. high-current, f/f 18650 with a capacity of 2000mah)

Own designations:
Panasonic NCR18650PF (NCR is a type of cobalt chemistry, something between the first and second classes, i.e., in simple words, LiNiCoO2 chemistry, without the use of Magrane. As if it does not fit a certain class, a kind of symbiosis has turned out. The advantage is high energy density with low thresholds up to 2.5-2.75V). This battery uses LiNiMnCoO2 chemistry, that is, it is already IMR high-current based on manganese, but the manufacturer left the old markings.
Sanyo UR18650FM – the information may not be accurate, but I came across information that Sanyo does not produce batteries for retail sale, and therefore does not bother with labeling. It produces cans for large electronics manufacturers, so the labeling is purely “for itself.” Perhaps, according to the company’s internal designations, UR and F(M) mean type, chemistry and capacity, at least there is no information in the datasheets (only that this is the model marking). And this is a lithium-ion battery with the usual cobalt chemistry, f/f 18650 with a capacity of 2600mah.

Selecting a 18650 battery

Now, after we have studied the main characteristics of batteries, let’s try to figure out how not to make a mistake when buying a battery and what type to choose for specific tasks. Many of us use flashlights and lamps with 18650 batteries, and some also have power banks for these types of batteries.
You should never take the word for the inscriptions on batteries of unknown, little-known or cheap brands.

A clear example of a battery with fantastic capacity

A person who doesn’t understand will immediately fall for it - that’s a fact. Be carefull!

Choosing a 18650 battery. Questions and Answers

If you need simple advice - which 18650 battery is better to buy without delving headlong into the technical component, “so that it just works normally”, we will answer this:

The most affordable in terms of price/quality ratio is the Samsung ICR18650-26F (or H) with a capacity of 2600mAh; most of your devices and flashlights will work on it without problems.

If you increase the cost budget for purchasing a battery by one and a half to two times, you can purchase an almost maximum capacity battery LG18650MJ1 (30% more):

Its analogues are Sanyo (NCR18650GA) and Samsung (INR18650-35E), and Samsung is noticeably cheaper.

If you need a record holder for capacity and quality, then this is definitely what we think at the moment: Panasonic NCR18650G 3600mAh

Protected and/or unprotected 18650 battery?

Attention! All items on this list are required!

We are talking about electronic protection against overcharge, overdischarge and short circuit. Details with pictures.

Batteries with protection must

• The lantern consists of two or more sequentially installed batteries. "Lantern-baton", like this.
• You are using a simple charger without an overcharge protection circuit and/or from little-known Chinese manufacturers.
• The flashlight is equipped with mechanical protection against polarity reversal of an incorrectly installed battery. For this, a battery with protection with a protruding positive contact is usually used (exceptions are possible, of course).
• The flashlight does not provide information or shutdown protection when the battery is significantly discharged - below 2.6 V, and you don’t want to bother with this (you can simply forget to turn it off).
• The flashlight may fall into the temporary use of forgetful and/or inexperienced people, as well as into the hands of your children and they will torture it until they lose their “pulse”).

Batteries with protection Can

• For flashlights powered by 18650 size batteries, if the protected battery fits freely into it in length (there are no problems with screwing the battery compartment cover) and in diameter (does not rest against the walls during installation).
• Powerful flashlight with parallel connecting two or more batteries. In our opinion, this is a controversial decision.

Unprotected batteries must used in the following cases:

• The battery compartment is too narrow or short in a flashlight designed for one 18650 battery(important!) (impossibility of installing a protected battery that is 2-3mm longer and 0.5mm wider).
• As a rule, a modern flashlight with powerful LEDs (xm-l2 xp-l2) powered by one The battery consumes a lot of current at maximum brightness (3 amps or more). And many protected batteries may simply shut down when turned on due to overcurrent.

Unprotected batteries Can use in the following cases:

1. The flashlight is designed for one battery or it runs on two or more parallel installed batteries.
2. A smart charger is used (smooth reduction of the battery charging current and the function of automatically turning off the battery after charging, selection of charging current, other functions) from trusted brands (liitokala, nitecore)
3. You will never forget to turn off the flashlight after use and/or will not leave it on for long periods of time unattended (unless it has built-in low battery protection).
4. Children do not have access to the Lantern and/or you do not trust others to use it without your presence.
5. You store batteries in a special box and do not throw them anywhere, due to which they can be accidentally shorted by metal objects or random current conductors.

Branded and/or Chinese 18650 battery?

Previously, purchasing a cheap Chinese (from a true Chinese brand) 18650 battery was justified. Several years ago, such batteries were much cheaper than branded ones, and in terms of characteristics they were close to their branded counterparts.
But time goes by. And starting from 13-14, some well-known brands, in order not to be left out, reduced the price so much that purchasing a “folk” battery from China of dubious quality in order to save money became irrelevant.
In 15-16 years, super-capacious batteries - one might say the flagships Panasonic 3600, due to fierce competition from Korean brands, reduced the price almost to the level of what had become popular at that time - Samsung.

Therefore, to the Chinese brand - manufacturer of 18650 batteries (Even if it is already quite popular) we can say: who are you? let's goodbye.

When choosing a battery, do not forget about this:

• There are only four main manufacturers of 18650 batteries from well-known brands: Panasonic, Sanyo, Samsung and LG. There is also Sony with its exotic models, but the ones mentioned above are the most common.
• All other brands (usually manufacturers of various flashlights) wrap the same Panasonic, Sanyo, Samsung and LG in thermal covers with the names and logos of their brand, well, maybe even providing these batteries with a protection board and/or modified contact pads.
• As a rule, after this they receive a noticeable increase in price, although they are no better in terms of characteristics.
• It’s true that it’s worth noting that sometimes such modified batteries can be better than their donors, since they should work without problems with flashlights from the manufacturer of the same brand (with others there may be problems due to size, contacts and current overloads).
• For some “special” flashlights, you need to purchase batteries that are recommended by the manufacturer or specified in the description/instructions for the flashlight.

Selection of capacity18650 battery

At the time of writing, large capacity according to real measurements has only one type of battery: Panasonic NCR18650G 3600mAh. What is more (there are fantastic inscriptions 4000, 5200, 9800 and even 12000!), and sometimes even quite real ones from little-known/unknown Chinese brands in fact black marketing and blatant lies our Chinese “friends” of underground production. Usually, bright labels and super inscriptions are used to hide the “pig in a poke.” On the fonarevka.ru forum, read the article Horrors of our town. In the best case, you will get working junk with a capacity of 1800-2000 mAh and a lifespan of six months to a year.

But even a branded battery with a really high capacity is not a panacea. It happens. that the operating time of the flashlight does not always increase noticeably with the installation of a high-capacity battery, and there are reasons for this. In everyday living conditions, a Samsung battery with a capacity of 2600 mAh can cope with the tasks at hand. It's an affordable workhorse for all conditions. If you are still leaning towards batteries of higher capacity (2800, 3200, 3400 and 3600mAh), adhere to the following rules:

• Purchase batteries only from well-known brands and manufacturers.
• Popular Panasonic Li-ion batteries are capable of delivering their full capacity when discharged to 2.5 v. The truth is worth noting. that not all flashlights and powerbanks are capable of working with such low voltage. All “baton flashlights” (with 2-3 18650 batteries installed in series) and flashlights of high-quality Chinese and other brands (Convoy, etc.) running on a single 18650 battery can cope with this.
• If you use high-capacity batteries from LG or Samsung, then they need to be recharged to their operating non-standard voltage of 4.35V (the standard voltage is 4.2V), most likely using an expensive “smart” charger. An example of such a battery is the LG ICR18650E1 with a capacity of 3200mAh.
• The LG INR18650-MJ1 battery with an announced capacity of 3500mAh is physically capable of working for a long time and quietly delivering high current to the load. Moreover, its operation is carried out in the range of standard voltages of 4.2 - 3.0V Li-ion batteries. Analogues of this battery are: Sanyo (NCR18650GA); Samsung (INR18650-35E).

From all of the above, we can assume that if any of these operating conditions for more capacious and expensive batteries are violated or not met, you will most likely get the same effect from their use and operating time as from the cheaper Samsung 2600. Be that as it may from the most capacious and most expensive ones, in an ideal situation and luck - it will shine only 10-30 percent longer than usual!

The estimated price in Chinese online stores at the time of writing is $2-2.5 for one Samsung 2600mAh can and $4-6 for the most capacious Panasonic 3400mAh - 3600mAh can. Good, high-quality protection will add another 1-3 dollars. You will have to pay a few more dollars for a beautiful wrapper from the lantern manufacturer.

The meaning of the inscriptions in English in the description of the battery 18650

• The battery capacity is designated " mAh". mAh – milli-Ampere-hour translated into Russian, as you may have guessed.
• Batteries with protection are marked " With protective PCB", "Protected", "Protection Circuit" and so on..
• Nothing is indicated about those who are not protected, or in rare cases they are indicated " Unprotected".
• Numbers indicating voltage 3.6V and 3.7V essentially mean absolutely the same thing. Represents the average voltage for a battery that needs to be charged to 4.2V. As a rule, the manufacturer decides for himself whether to indicate one or the other value.
• If the voltage is indicated on the label or in the description 3.8V then this means that the battery should be charged to non-standard 4.3 or 4.35 Volt.
• Voltage value 3.2 V usually denoted Lithium iron phosphate battery . If you haven’t heard of this and don’t know what its purpose is, just forget about it, most likely you won’t need it.

Cases of counterfeit 18650 batteries

There have been almost no cases of counterfeit batteries from the main brands: Samsung, Sanyo, LG and Panasonic. But with other brands you need to be more careful - the situation may be different.

Attention! There have been cases of unscrupulous sellers selling old, worn-out batteries from the dismantling of large batteries from electric cars or electric bicycles.

You can determine the manufacturing date using the manufacturer's code on 18650 batteries using this link:
https://batterybro.com/18650-date

Suitable for:
Samsung
Sony
Panasonic
Sanyo
LG

Signs of such batteries:

• Remnants of removed contact welding on the poles (scratch spots on the ends)
• Remains of sealant (glue) on the battery case

Applications

Table of characteristics for famous brands

Materials used in the article

P.S. I’ll add on my own behalf as a person who has been using this type of battery for a long time - Take Liitokala, Sanyo, LG, Samsung or Panasonic!

DO NOT TAKE UltraFire or worse, especially with a capacity higher than 3000mAh

I welcome everyone who stopped by. The review will focus, as you probably already guessed, on the removal of protection boards from lithium-ion batteries of the 18650 form factor, in particular Sanyo UR18650FM 2600mah and Panasonic NCR18650PF 2900mah. There was a review on Muska where the author put protection, but there seemed to be no reviews of removal. I hope this review will be useful to someone. I probably agree with those who say that this operation is a mere trifle and it was not worth writing a review about it. But, as practice shows, some are afraid and do not dare to remove the protection. If you are interested, please see cat.

A small educational program on Li-ion batteries in a free interpretation:
First of all, the battery is the primary power source, i.e. it generates energy itself. In our case, it converts chemical energy into electrical energy. The first lithium-ion battery was released by Sony in 1991 (with ViKi). If anyone thinks that these batteries are something unusual and even dangerous, then I dare to reassure you, these batteries have long been installed in various electronic gadgets, from phones to laptops, the batteries just have different form factors.
In mass production, three classes of Li-ion batteries are used (based on the cathode material, the second letter in the marking):
1) lithium-cobalt LiCoO2 (the most common, the highest capacity among Li-Ion)
2) lithium-manganese LiMnO2, LiMn2O4, LiNiMnCoO2 (better known as high-current (INR), capable of delivering currents of 5-7C to the load, which are usually inferior in capacity to the former)
3) lithium ferrophosphate LiFePO4 (excellent batteries undervalued by the market, in all respects they undoubtedly outperform the first two types, except for operating voltage and capacity, it is even lower than that of INR)
As they say, all three classes are tailored to perform specific tasks and have their pros and cons.

Since there are no uniform battery labeling standards, all manufacturers label them differently. But ideally it should be something like this:
1) the first letter is the manufacturing technology (I - lithium-ion technology)
2) second letter - type of chemistry, cathode material (C/M/F - cobalt/manganese/iron phosphate chemistry)
3) third letter R - battery (rechargeable)
4) five digits - form factor (the first two digits are diameter, the next two are length, the last digit is the shape of the acca (0 - cylindrical))
- 10430 (everyone’s familiar “little fingers”)
- 14500 (everyone’s familiar “fingers”),
- 16340 (size like a CR123 battery),
- 17335 (not common)
- 18500 (also not very common)
- 18650 (the most common form factor on the market),
- 26650 (enlarged, came to the market from the company A123 Systems, which produces lithium ferrophosphate batteries)
- 32650 (absolutely monsters, only for stationary devices, weight almost 150g)
- plus unofficial f/f with protection boards, for example 18670...
5) letters/numbers - specific marking of the container (different for all manufacturers)

An example of marking, but as a rule, it is different for all manufacturers:
- Samsung ICR18650-26F (lithium-ion battery with the usual cobalt chemistry, f/f 18650 with a capacity of 2600mah)
- Samsung INR18650-20R (lithium-ion battery with manganese chemistry, i.e. high-current, f/f 18650 with a capacity of 2000mah)

Own designations:
Panasonic NCR18650PF (NCR is a type of cobalt chemistry, something between the first and second classes, i.e., in simple words, LiNiCoO2 chemistry, without the use of maranz. Although it does not fit a certain class, a kind of symbiosis has turned out. The advantage is high energy density with low thresholds up to 2.5-2.75V). This battery uses LiNiMnCoO2 chemistry, that is, it is already IMR high-current based on manganese, but the manufacturer left the old markings.
Sanyo UR18650FM – the information may not be accurate, but I came across information that Sanyo does not produce batteries for retail sale, and therefore does not bother with labeling. It produces cans for large electronics manufacturers, so the labeling is purely “for itself.” Perhaps, according to the company’s internal designations, UR and F(M) mean type, chemistry and capacity, at least there is no information in the datasheets (only that this is the model marking). And this is a lithium-ion battery with the usual cobalt chemistry, f/f 18650 with a capacity of 2600mah.

Now briefly about what protection is and where it is usually located:
Protection is a special board, often located on the negative terminal of the battery. It protects the battery from short circuit, overcharge and overdischarge, breaking the supply circuit. Characterized by three parameters:
- cut-off voltage when charging (4.25-4.3V)
- cut-off voltage during discharge (2.4-2.7V)
- throughput current (mainly depends on the number of mosfets on the board)
As an example, a datasheet for a simple protection:

What is the board:







Photo of protection on the negative contact (most common):




Photo of protection on the positive contact:

Some important notes on Li-ion

There are no Li-ion batteries in the 18650 form factor with a capacity of more than 3600mAh. All ****Fire with bright numbers 4000-5500mah are just fakes. Inside there are either rejects/recycling batteries, or batteries of a smaller capacity, and sometimes of a different form factor altogether (inserted into the 18650 like in a Russian nesting doll with sand for weight), covered with colorful shrink film. At the time of writing, only the Panasonic NCR18650G had a maximum capacity of 3600mah. Even batteries with increased voltage to 4.35V do not reach this capacity.
Pornoslonik at 3600mah (not yet found in retail):


But UltraFire at 2400mah and 3000mah:




- Large manufacturers do not produce protected batteries. Their factories always produce unprotected cans for use in battery assemblies and other devices. Other companies install the protection board, often covering the can with their proprietary heat shrink.
As an example of Keeppower, just above there was unnamed China


As we can see, both batteries have the well-known Panasonic NCR18650B inside, only the first one has the highest quality protection and the banks are from more successful batches, while the second one is typical of China.
- manufacturers divide the elements inside the battery into three quality classes (this information is not included in the battery labeling, only within the manufacturing company)


- a convexity (notch) in the area of ​​the positive contact of the battery is not protection; it is a structural feature of all Li-ion. Also, the bulge on the positive/minus contact itself does not indicate the presence of a protection board, it is just the type of contact.


This is the same notch that some people mistake for a protection board):


Two identical unprotected Panasonic NCR18650B with different contacts:




- Evaluating a battery only by its capacity is a big mistake. You need to compare based on the stored energy, as well as the lower voltage threshold. For example, the very popular NCR18650B porno with a discharge current of 0.5A shows a capacity of 3270mah (11.85W), and with a 3A discharge it is already 3100mah (10.7W), but a specific voltage drop is observed. In addition, most devices do not know how to discharge the battery below 2.9-3V and simply turn off, this must be taken into account.
- Li-ion batteries do not have any memory effect, so they can be charged without waiting for them to discharge to zero. According to information from the Internet, if you charge the battery at 70-80%, i.e. do not discharge below this threshold, then the number of cycles increases from 500-600 to 1000.
- Li-ion batteries have some self-discharge, so to reduce the impact of this effect during long-term storage, batteries should be stored in a slightly discharged state in a cool place (15 degrees). Those. The charge level should be around 75%.
Loss of capacity during storage (with ViKi):


- periodically you need to discharge the battery, once or twice every couple of months.
- Li-ion batteries do not like low and high temperatures, so in the cold, ordinary lithium drains the capacity greatly, and when exposed to high temperatures, the resource is greatly reduced.
- absolutely all Li-ion batteries have a safety valve to release excessive pressure when the can overheats.
- Well, from personal experience. The devil is not as scary as he is painted. I accidentally shorted the LG can from my laptop. It was a bit of a search, nothing more. No explosion, etc., as ardent fans of protected batteries write about

So, enough chatter, let's get back to the main topic, which is removing the protection board.
Why is “castration” actually needed:
- To reduce energy loss on this board. For example, in single-can flashlights this is quite critical, so it is preferable to use batteries without protection there, because all conductors and protective elements are something other than resistance. And at high currents, even a tiny resistance can greatly spoil the picture. For example, with a current of 2.8A in some area with a resistance of 0.2 Ohm, we will have a drop U=I*R=2.8*0.2=0.56V. Stabilization on mikrukh AMC7135 (national Nanjg drivers) will continue until the voltage on the bank drops to 3.8V (approximately), then the brightness of the flashlight will gradually decrease.
- For DIY device assemblies. Suppose the battery built into the power bank (PB) has a capacity of about 1 Ah and, therefore, the PB is of little use and you decide to replace the built-in battery. But having disassembled the power bank, we saw that the current collectors were welded to the battery contacts by spot welding, and after reading on the Internet about the dangers of soldering the battery contacts, we came to a dead end (the new battery will have to be soldered to these current collectors). This is where this operation will help. If the power bank has built-in protection against overcharge/overdischarge, then to get out of this situation, we simply buy a battery with protection. When removing it, we save the conductors welded to the battery contacts and solder the current collectors of the power bank to them. As a result, we do everything safely and preserve the appearance of the battery (you can later replace it with a more capacious one, and use this one for other needs, simply tearing off the conductors and there will be no solder on the contacts).
- The protected battery is not included in the flashlight/charger/PB/other device. This applies to budget shitty fireers, there is such a problem, or budget chargers, for example, the Miller ML-102, which I recently wrote a review about. They are often designed for unprotected banks (there are quite a few similar devices).
- The device consumes excessive current and due to this, the current protection is activated. In ordinary boards, on average the shutdown threshold is 5-6A, but it can also be around 2.5-3A (in a powerful 2.8A flashlight this will already be a problem).
- The protection board does not operate correctly, i.e. the charger finishes charging before or turns off earlier when the device is discharged. This also happens, especially with Chinese protection. For example, a branded charger fills, as expected, up to 4.2V, but the protection board responds earlier, say at 4.18V, which means the battery is slightly undercharged (although the boards are designed for 4.25V). It's rare, but still unpleasant.
- To reduce the self-discharge of the can. The board consumes a small current in sleep mode.
- Batteries with protection are safer, which means they are more in demand on the market. Consequently, they do not sit in store warehouses and are constantly updated. Due to the ban on lithium transportation, the number of stores guaranteed to send lithium is noticeably reduced. And there may be a situation when batteries without protection are needed, and the store’s assortment includes only fresh protected batteries and stale unprotected ones (or none at all). And as you know, lithium ages quickly, so the choice falls on protected ones, although they are not needed. And with small movements, they turn into unprotected (here, of course, there is a slight overpayment for protection, but you have to sacrifice something, either durability or cost).
- Well, and most recently, when the protection board simply burned out/damaged. Nothing works with her at all.
In general, there can be a lot of reasons, or it can be trivial, your hands are just itching...

So, our students:
Sanyo UR18650FM (bought for a finished shitfire without overdischarge protection)
+ very high quality (it’s not for nothing that they call it folk)
+ good discharge curve (behaves well with current load)
+ inexpensive
+ no fakes
- the capacity is slightly less than declared (especially at current load)
- weak (thin) positive contact (in devices with a rigid spring it bends)
- not frost-resistant (new version UR18650ZY - frost-resistant)
- sometimes you come across stale ones

Castration Sanyo

Photo with protection:


So, first we cut off the edge of the folded heat shrink. Next, we decide whether this external heat shrink is needed (it can be useful for additional protection, as well as to prevent the can from flopping around inside a device, for example, a flashlight).


If you decide to leave it, then carefully pick out the plate holder. The edges of the heat shrink will dangle, then you can heat them and they will press against the body. I don't need protection, because... The battery will be used in the Convoy M1 flashlight, and additional energy losses are not needed there, and it also has overdischarge protection.


We tear off the plastic washer (it looks like I didn’t take a photo of it), but you can leave it as is if you need a convex positive contact:


I didn’t need a convex contact, so carefully bend the positive contact with a screwdriver (it is important not to short-circuit the positive contact to the negative body):


As you can see, the positive contact is held on only one current lead and is pressed with a plastic washer with heat shrink:


Because My outer heat shrink was already worn out, so I decided to cover the jar with new heat shrink. Therefore, we simply rip off the old one:


We see a conductor glued to adhesive tape (yes, yes, you can’t just push it out from under the old heat shrink):


Let's tear off all this stuff:


We observe the remains of the glue that was used to glue the plastic washer. The glue can be easily removed with alcohol/acetone:


We borrow a regular hairdryer from our wife/friend and heat up the heat shrink. Anyone who has a hair dryer/soldering station is in trouble. They do everything efficiently and quickly. All irregularities will be pulled together. It is important here not to heat the contact too much; a couple of seconds is enough for the heat shrink to shrink.


This is the protection board that was installed in the People's Bank with BIC:


All protective elements (the puck has disappeared somewhere):


If desired, we pack the jar in new heat shrink. You can buy it here
To do this, we cut off the new heat shrink at a right angle, leaving a margin of 3-4 mm on the sides. If the ends of the tube are crooked, it will not lie flat when heated. Because the tube is sent in a twisted state (reel), then when you put it on the jar, you should not smooth out the sharp ends, otherwise after the “shrinkage” two unsightly stripes will remain along the battery:


Warm it up carefully. The main thing is to move the hairdryer smoothly and not to jump from one place to another, otherwise there will be small “spots”:






That's it, the battery is ready for work and defense:

Now it’s the Panasonic NCR18650PF’s turn (bought to replace the built-in battery in the Power Bank)
+ good quality (Sanyo is a subsidiary of Panasonic, they merged in 2009)
+ good current output (this is a high-current IMR battery, capable of delivering up to 10A)
+ quite affordable price for such a capacity
+ reinforced positive contact
± low discharge threshold of 2.5V (similar NCR18650PD has a discharge threshold of 2.75V)
- not frost-resistant

Castration Panasonic

Photo with protection






In my case, current leads were important to me, because... in case of an unsuccessful attempt to assemble the PB, the battery would be used in the flashlight, and the tinned contacts on the battery are not good. In principle, there is nothing complicated in direct soldering directly to the contacts, the main thing is to have a 40-60W soldering iron, flux and do everything quickly.
So, we rip off the heat shrink:








Because I needed current leads, so I bit them off with side cutters to the very root, i.e. at the board itself:




Using a thin screwdriver, or better yet, plastic cards, disconnect the plastic washer:


If you need a convex contact, as I wrote above, then carefully break off the down conductor by numerous bends and put the washer back. In my case, I don’t need it; with such a contact, this battery simply does not fit into the cylindrical PB, so we tear everything clean off:




We bite off the long conductor, it will still be useful in the future PB:


Here's what happened:




And here was the following protection board:

This battery will be wrapped in heat shrink along with the PB guts.

General Notes:
Often, you can simply remove the protection contacts (plus and minus) and the board itself, and leave the transparent/colorful heat shrink along with the conductor (yellow stripe along the body) as additional protection for the battery case. The conductor itself cannot be pulled out from under the heat shrink; it is glued to the tape. You can solder anything to the contacts of the protected battery; there is a gap there, so the can itself is not in danger of overheating. The protection must be removed carefully, without short-circuiting the conductors.

Actually, why did I remove the protection? My first flashlight with a powerful LED was a cheap shitfire. Later, having felt the flashlights, I purchased better ones, but these cheap ones, although they were improved, were still not up to the level of a good product. Therefore, it was decided to put them in the garage/garden. They were rarely used and installing a driver with protection in them was not entirely advisable. Therefore, a basic stabilizer was made without overdischarge protection (cheap and cheerful), and using a can without protection in such a flashlight was dangerous. That's why batteries with protection were purchased. But recently the fleet of flashlights has been replenished and the modified flashlights have retired. But banks with protection turned out to be unnecessary. This is all about Sanyo. The story with the can of pornoslonika is a little different. It was purchased as a replacement for the battery built into the PB. Maybe I’ll tell you how I installed the porn elephant in the PB in the next article...

And more additional information on batteries:
Photo of discharge in comparators:
Let's compare our players with their brothers who have the best price/performance ratio


Because I don’t know how to insert a large photo into the review, so I’ll explain:
Discharge current 3A to 3V:
- The undisputed leader LG ICR18650D1 3000mah 4.35V (10Wh, the voltage holds perfectly, the capacity is 3000mah, i.e. in theory it should hold 3A - 60 minutes, in the test - 3400 sec/56-57 minutes, measured capacity at 3A - 2840mah).
- Next comes the popular bank Sanyo UR18650FM 2600mah 4.2V (8.65Wh, the voltage holds a little worse than the Ski, but there is a high threshold of 4.35V, for 4.2V batteries it’s just fine, the capacity is 2600mah, i.e. in theory it should hold 3A - 51.6 minutes, in the test - 2960sec/49.5 minutes, measured capacity at 3A - 2473mah. As you can see, a little less than stated, but the parameters are simply excellent).
Next is our Panasonic NCR18650PF 2900mah 4.2V (8.89Wh, the voltage holds perfectly, at first it even surpasses the Sanyo, the capacity is 2900mah, i.e. in theory it should hold 3A - 58 minutes, in the test - 3054 sec/51 minutes, measured capacity at 3A - 2551mah. As you can see, it is much less than stated, but it has a discharge threshold of up to 2.5 V (in the test up to 3 V). This is the whole trick of the Panos, that many devices will not take the entire capacity from a porn elephant, and the price is higher than Sanya and Samsonov).
And the latest Samsung ICR18650-26F 2600mah 4.2V (8.73Wh, the voltage holds a little worse than the Sanyo, but the capacity is a little larger, plus it costs mere pennies, the capacity is 2600mah, i.e. in theory it should hold 3A - 51.6 minutes, in the test - 3036 sec/50.6 minutes, measured capacity at 3A - 2538mah. As you can see, Sanyo is better, and when compared with Pornoslonik 2900mah it is the same).
Here is a comparison in another comparator between Sanyo and Samsung (unfortunately, our Panos is not in it):

A little information about the production date of Sanyo cans:
According to the official datasheet:


My jar was marked UR18650FM S15B, i.e.:
- UR18650FM – let it be the model name
- the first letter is the year of manufacture: A – 1996, B – 1997…. O – 2010, P – 2011, Q – 2012, R – 2013, S – 2014, T – 2015, etc.
- the next two digits indicate the week the can was released: week 15 - mid-April
- the third letter is the technological line.
Total: Sanyo UR18650FM S15B production date - April 2014.

A little information about the production date of Panasonic cans
My jar was labeled NCR18650PF 4307 (bottom line, four characters), i.e.:
- NCR18650PF – let it be the model name
- the first digit is the year of manufacture: 1 – 2011, 2 – 2012, 3 – 2013, 4 – 2014, 5 – 2015, etc.
- the next digit is the month of issue: 1 – January, 2 – February, 9 – September…… X – October, Y – November, Z – December
- the third and fourth digits are the day of the month: 05, 14, 29.
I don't know what the capital letter means. Maybe either a technological line, or a quality class, or a place of production. In general, I don’t know, but it’s interesting.
Total: production date of Panasonic NCR18650PF 4307 – March 7, 2014.

A little information about the production date of Samsung cans:
Old datasheet:


For example, marking SAMSUNG ICR18650-26F 2CB3 (bottom line, four characters), i.e.:
- ICR18650-26F – let it be the model name (according to the “standard”)
- the first digit is the branch of the company where the battery was manufactured (not interesting)
- the second digit is the year of manufacture: Y-2005, L-2006, P-2007, Q-2008, S-2009, Z-2010, B-2011, C-2012, D-2013, E-2014, F- 2015, G-2016, H-2017, etc.
- the third digit is the month of issue: 1 – January, 2 – February, 9 – September…… A – October, B – November, C – December
- the fourth digit is the week the can was produced: 1, 2, 3, 4 and 5
Total: production date of SAMSUNG ICR18650-26F 2CB3 – 3rd week of November 2012.

A little information about the production date of LG cans
For example, the marking is LG ICR18650D1 3000mAh L040B097A1 (the first four characters are needed), i.e.:
- LG ICR18650D1 – let it be the model name
- the first digit is the year of manufacture: J – 2010, K – 2011, L – 2012, M – 2013, N – 2014, etc.
- the next three digits are the day of issue: 040 (40th day), it’s inconvenient to calculate...
Total: production date of LG ICR18650D1 L040B097A1 – February 9, 2012.

PS, all the information was found on the Internet at different times and recorded in a text file (I always add useful information this way). I don’t remember exactly what resource I found it on, so don’t even ask :)

What is a 18650 battery?

What is a 18650 battery? Sometimes it is also designated 168A.

To answer this question, it is necessary to study its characteristics and provide examples of use.

Recently, this type of battery has been gaining popularity as it provides the necessary voltage and capacity. In shape it resembles “finger” AA and “pinky” AAA batteries. The output voltage is 3.7V. Typical capacity: 2200-3000 mAh. AA and AAA batteries have a voltage of 1.5V (AA and AAA batteries have a voltage of 1.2V).

Most often it is a li-ion battery. The advantages include:

High energy density.
- Low self-discharge.
- No memory effect.
- Easy to maintain.
- Low specific gravity.

There are also disadvantages. Li-ion batteries are susceptible to failure when overcharged and/or overheated. To solve this problem, all household batteries are equipped with a built-in electronic circuit that prevents overcharging and/or overheating due to charging.

If not handled carefully, batteries can fail more often than other types of batteries. A full discharge “kills” a lithium-ion battery. After which it will be impossible to restore the battery.

Optimal storage conditions for Li-ion batteries are achieved at 40% charge of the battery capacity at a temperature of about 5 degrees Celsius. At the same time, low temperature is a more important factor for small losses of capacity during long-term storage. The average shelf life (service) of a lithium battery is on average 36 months.

Another feature of these batteries is aging. Lithium batteries age even when not used.

Lithium polymer and lithium ion batteries lose capacity when charged, unlike nickel and nickel metal hydride batteries. The higher the battery charge and the temperature during its storage, the shorter its service life. It is better to store them charged at 40-50%, and at a temperature of 0-10 degrees. Overcharging, like overdischarging, “burns out” the battery capacity. (Wikipedia).

And although it resembles the fingers and little fingers, its size is much larger. Length 66.5 mm. Pay attention to the line “With Re/Discharging Protection Circuit” (the battery has protection against complete discharge overcharging). When the voltage is more than 4.25V, the protection board blocks charging so as not to damage the battery. The same thing happens at a voltage less than 2.75V. A small thickening near the positive contact is the battery protection board.

Diameter - 18mm. For comparison, let’s write side by side the sizes of 2 other types of batteries:

AAA: 44*10.5mm

18650: 66.5*18mm

This is what AA, AAA and 18650 look like together.

Used where large capacity is needed. In our example, these are LED lights. The left light has a AAA battery, the middle one has an AA battery, and the right light has a CREE SST-50 LED. It requires a lot of power to operate. The 18650 battery is ideal, which is why the flashlight is made for it. Some flashlights are designed so that instead of an 18650 battery, you can install an adapter for 3 AAA batteries. In this case, the voltage is almost the same: 3.7V and 4.5V (=1.5V*3). In this case, of course, there is a loss of battery capacity.

It should also be noted that it is from these elements that laptop batteries are assembled.

We encounter electricity every day. It so happens that everything around us, from light bulbs to cars, uses electrical energy. Household appliances around us are connected to a 220 V network. But besides them, there are also mobile devices that we take with us to work or on a trip. These devices also require electricity.

Autonomous power supply for devices or power tools can be provided by a battery. The very name of the device speaks about its purpose to accumulate (accumulate) electric current. The larger the battery capacity, the longer the consumer can work. Production technologies are improving every day. 18650 batteries become more powerful, hold operating voltage longer and reduce the time required to charge.

We have compiled a list of the best 18650 batteries based on expert reviews and reviews from real customers. Our recommendations will help you make a choice that suits your needs and desires. There are many competitors in the global technology market, but we have selected the best manufacturers and recommend paying special attention to them:

1. ROBITON
2. Bright BEAM
3. Rexant
4. Samsung
5. Panasonic

*Prices are correct at the time of publication and are subject to change without notice.

18650 batteries: For flashlights

For lanterns / Capacity: 2000-3000mAh / Capacity: up to 2000 mAh/ With protection

Main advantages

• High-capacity lithium-ion battery weighing less than 42 grams with built-in surge protection while charging the device
• The marking on the battery “With Re/Discharging Protection Circuit” indicates that the protection system blocks charging current exceeding 4.25 V or less than 2.75 V to preserve battery functionality
• Designed for installation in devices that require large battery capacity, such as high-power LED lights or rechargeable batteries in laptops
• The battery has a high efficiency (about 90%), which indicates its high energy intensity and good performance characteristics
• Compact dimensions allow the battery to be used in small devices and devices of portable or stationary type

For lanterns / Capacity: 2000-3000mAh/ With protection

Main advantages

• Rugged battery based on the powerful original Samsung battery for use in high power consumption devices
• The lithium-ion battery does not have a “memory effect” and does not lose capacity if the charging mode is violated. Regardless of these cycles, the current is supplied completely during operation
• The battery is equipped with protection against current fluctuations during overcharging or overdischarging, which prevents its failure and extends its effective service life
• Manufactured to strict standards so the battery's exact diameter is suitable for use in e-cigarettes whose design limits the battery's allowable size
• Thanks to the Li-ion electrochemical system, batteries of this type are not afraid of frequent recharging. Battery capacity of 2200 mAh (3.7 V) is enough to power most compact devices

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18650 batteries: For screwdrivers

For lanterns / For screwdrivers / Capacity: up to 2000 mAh/ With protection

Main advantages

• Battery with a rated power of 1100 mAh and an operating voltage of 3.2 V is ideal for LED flashlights
• Innovative Nanophosphate® technology ensures stable operation of the battery regardless of environmental changes. Does not require cooling in case of overheating and heating in extremely low temperature conditions
• The ability to operate in a wide range from - 20 to + 60 and store from - 20 to + 45 degrees Celsius significantly expands the scope of application of the battery
• Allows fast charging within 12 minutes, which is carried out with a high current of 4 A
• A high degree of battery operating safety is ensured due to the thermal and chemical stability of the device

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18650 batteries: For power banks

For power banks/ For lanterns / Capacity: 2000-3000mAh/ With protection

Main advantages

• Battery with lithium-ion electrochemical system for installation in flashlights or other high-power devices
• Built-in protection against voltage surges during charging and discharging cycles protects the battery from failure and extends its service life
• Does not have a negative “memory effect”. This eliminates loss of capacity in case of violation of the correct charging cycle and incomplete discharge during operation
• Sufficiently large capacity of 2800 mAh (3.7 V) ensures long and efficient service life of devices
• The compact dimensions of the battery allow it to be used in small-sized mobile devices and facilitate storage and transportation

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18650 batteries: Capacity: 2000-3000 mAh

For lanterns / Capacity: 2000-3000mAh/ With protection

Main advantages

• Protected 2600mAh lithium-ion battery based on Sanyo 3.6V
• Designed for use in professional YLP series flashlights with a single 18650 battery that do not include a battery or charger
• To improve ease of use, the battery is equipped with a charging board, which is connected via a micro-USB connector.
• Built-in indicators allow you to visually monitor battery charging. This can be useful in low or no light conditions
• The compact dimensions of the power supply (diameter 18.6 mm, length 70 mm) facilitate storage and transportation. The battery is packed in a bright gift-type blister

Show all products in the category "Capacity: 2000-3000 mAh"

18650 batteries: Capacity: over 3000 mAh

For power banks / For screwdrivers / Capacity: over 3000 mAh/ Solderable

Main advantages

• Unprotected high capacity lithium battery capable of delivering high discharge current in a relatively small size
• Has a fairly long service life. The battery confidently withstands up to 500 charge and discharge cycles before the energy capacity drops to 80% of the nominal value
• For use, it requires the installation of a special board (PCM), which protects the battery from overcharging or overdischarging and protects against premature failure
• When installed in devices that have a built-in battery condition monitoring function (for example, all Armytek line flashlights), a protective board (PCM) is not installed
• The battery is demanding on charging and discharging currents. They should not exceed 4.2 - 4.35 V (charging) and 2.5 - 2.7 V (discharging). Failure to comply with these conditions will result in battery failure.

For power banks / For screwdrivers / Capacity: over 3000 mAh/ Solderable

Main advantages

• Industrial (unprotected) 18650 lithium-ion battery with a capacity of 3400 mAh and a nominal voltage of 3.6 V
• The batteries have a maximum real capacity in 18650 format and the ability to support high load current without reducing voltage
• Most top brands of laptops are equipped with batteries of this model. Thanks to the presence of these batteries (Battery Pack), the devices are subsequently able to operate in autonomous mode for quite a long time
• The special chemical composition of the battery prevents fire even if the cell is damaged
• Has high efficiency and a long service life of up to 500 discharge and charge cycles, with a loss of capacity of only up to 80% of the nominal

For lanterns / Capacity: over 3000 mAh/ With protection / For screwdrivers

Main advantages

• Protected Li-ion battery size 18650 with a large capacity of 3400 mAh and a maximum discharge current of 6.8 A. Based on the original Panasonic 3400 mAh battery
• Does not have a negative “memory effect”. The discharge and charge capacity does not depend on the residual capacity. Does not require strict adherence to charging cycles
• Equipped with a protection board that avoids current fluctuations when restoring capacity. This extends battery life and prevents battery failure
• Ideal for Battery Packs for laptops or power tools
• Battery with high efficiency and long service life up to 500 recovery cycles. This confirms its high energy intensity and excellent performance characteristics.