What voltage to charge lipo batteries. Everything about LiPo batteries: charging, operation, storage

In this article, based on recommendations from many pilots and mini quad racers, we will show you some great LiPo battery chargers. The selected chargers are reliable, easy to use and have a wide range of capabilities.

Portability is another criterion important for minicopter pilots, because... In the field, you also need to charge batteries.

Other popular components for racing copters can be found using the “ “ tag.

iSDT series chargers

iSDT Q6 Plus 300W

• Buy on Banggood | Amazon | GetFPV | RDQ
• Review

iSDT SC-608 150W

• Buy on Banggood | Amazon
• Review

iSDT D2 200W 2-Channel

Without a doubt, iSDT chargers are very popular in our group. There are 3 options with different maximum power, they will suit most pilots. The color screen user interface is easy to use. For the specified power they are quite compact.

All three chargers are portable and easy to use in the field. However, these are relatively new chargers, so make sure you have the latest firmware with all the fixes and improvements. Here .

Minor drawback The problem with these chargers is the lack of a power supply. It must be purchased separately. For example, this one.

I bought an inexpensive and lightweight power supply for laptops (100 W) on ebay, which is convenient to take with me on trips. Thanks to the wide input voltage range, many different power supplies will fit. The output connector can be slightly modified and an XT60 can be added.

The D2 is essentially two chargers in one case, it can charge 2 different batteries at the same time, or you can connect 2 different parallel charging boards to it. Plus, it has a built-in power supply so it plugs directly into an outlet.

Update (August 2017). Models SC608 and SC620 are no longer in production. They can still be found on sale, but there will be no more firmware updates. IMHO, it still makes sense to take them.

SkyRC iMAX B6 Mini

• Buy on Banggood |AliExpress

A simple, budget charger. The B6 Mini is an updated version of the old and well-known B6, which was one of the most popular chargers. There are a lot of fakes out there, so make sure you get the original one.

SkyRC Q200

• Buy on Banggood | Amazon |AliExpress

The main feature of SkyRC Q200 is 4 independent channels, i.e. it is equal to 4 separate chargers. This means you can charge 4 different batteries at the same time! This is simply great, especially for those who do not want or cannot charge several batteries connected in parallel. Well, or if the batteries have a different number of cells.

Has a built-in power supply, as well as an input direct current, i.e. it can also be used in the field. The disadvantage is that it weighs about 1.3 kg.

You can even connect this charger to your computer or smartphone to control it and monitor the charging process.

Turnigy Reaktor 300W

The Reaktor 300W has a built-in power supply as well as a DC input. This is definitely one of the most reliable chargers out there.

Don't like parallel charging boards? Then pay attention to SkyRC E4Q! This is an inexpensive 4-channel charger. Perfect for charging batteries in glasses/helmets.

It has an input with an XT60 connector, and due to its small size and weight, it is perfect for working in the field.

I hope these tips were helpful. We'll keep an eye out for new devices and try to keep this list up to date. Write if you have any questions.

Measurement history

• July 2017 - first version of the article
• July 2018 - SC620 removed (discontinued), SkyRC E4Q and iSDT D2 added

Many novice modelers sooner or later have a question about what LiPo batteries are, how to select them, charge them, how to properly use and store a lithium polymer battery.

This article was created to provide simple and accessible answers to questions that concern newbies regarding batteries of various models.

What is a LiPo battery will Wikipedia help us figure out?

Quote from Wikipedia:
“The lithium-ion polymer battery (lithium-ion polymer battery; abbreviations: Li-pol, Li-polymer LiPo, LIP, Li-poly, etc.) is an improved design of the lithium-ion battery. A polymer material with inclusions of a gel-like lithium-conducting filler is used as an electrolyte. Used in mobile phones, digital technology, radio-controlled models, etc.

Conventional household lithium-polymer batteries are not capable of delivering high current, but there are special power lithium-polymer batteries that can deliver current 10 and even 130 times the numerical value of the capacity in ampere-hours. They are widely used as batteries for radio controlled models, as well as in portable power tools and some modern electric vehicles."

How to choose a LiPo battery? Basic criteria for choosing a lithium polymer battery.

Battery labeling will help us with this. It is indicated by the manufacturer on each Akuma. For example, Turnigy nano-tech 2200mah 3S 25C Lipo Pack, where:

• Turnigy - manufacturer
• nano tech – model/production technology
• 2200 mah – full capacity batteries
• 3S - number of cans, cells (1 can = 3.7v)
• 25C – current output ( maximum current rank)

1C - one battery capacity. For our example, 2200 mah (or 2.2A)
A - ampere

Total for this battery we get: 25 x 2.2A = 55A

Therefore, the power supply system of the radio-controlled model in which this battery will be used must have a maximum current in the electrical circuit of less than 55A, preferably with a margin of no more than 45-50A.

If the current consumption of the model is close to 55A, then the above battery will quickly fail.

The first sign of failure is a swollen LiPo battery. You can restore functionality by placing the battery in the refrigerator or basement and making a pair. But the battery life will no longer be the same.

We would like to especially note that LiPo batteries are one of the most dangerous batteries; they must be handled with extreme care and attention. Any shock, heat, overdischarge or overcharging may cause the battery to catch fire or explode.

• Damage the outer shell
• Charge with high currents
• Discharge below 3V
• Be exposed to heat or overheating during use

ChargerLiPobatteries.

Charger for LiPo batteries.

LiPo batteries should be charged using special chargers (chargers) with a balancing mode.
Recommended chargers are:

Charger/balancer IMAX-B6(professional, original)
Charger/balancer budget version IMAXRC-B3 (budget version, original)

The manufacturer is SkyRC. There are many fakes and copies of memory data. Which often burn and cause batteries to catch fire. Therefore, it is better to buy original products. You can check it using the code on the hologram.

Most full-featured chargers have several LiPo charging modes:

• Charge
• discharge
• Balance
• Storage

To store batteries, you need to infect them in “Storage” mode. The charge level will be set to approximately half, which will ensure optimal storage conditions.

Everyday battery charging, if there are more than 2 batteries, should be done exclusively in the “Balance” balancing mode.

To start the charging process you need:

• Select the S number of your battery (2S, 3S, etc.)
• Set the current strength - A (1A, 1.1A, etc.)

And wait for the charging process to complete.
It is important not to leave this process unattended!

How to charge LiPo batteries.

It is worth noting that there are Akums with a charge current of 2C and even 5C. For them, the recommended indicators will be higher. See the information provided by the manufacturer on the battery itself.

LiPo batteries have 2 power wires:

• Power red +
• Power black —

As well as a balancing cable (2S and higher).

The balancing wire is used to charge all cans evenly.

On a quadcopter or any other model, a low battery indicator (beeper) is usually connected to this connector. On-board battery low alarm (1S-8S) with loud sound signal and an indicator showing voltage.

Let's look at an example: Turnigy nano-tech 2200mah 3S 25C

The 1C current is 2.2A, but the optimal charging current for the battery would be 1-1.5A.

The battery will take longer to charge than with a current of 2.2A, but its service life will be increased.

If the charge current exceeds 1C, the risk of battery explosion and fire increases.

At first, you can get by with a regular saucepan or any metal container.

StorageLiPo batteries.

The batteries must be stored charged at 40-60% (the voltage will be about 3.8v per cell).

Long-term storage of a fully charged or completely discharged battery will lead to its failure.

Recommendations for proper storage LiPo batteries:

• Switch the battery to Storage mode
• Avoid direct sunlight
• Keep the storage temperature within 0..+10°С (refrigerator temperature), or +5..+28°С (room temperature). The second option is less preferable.
• Store in a special bag, fireproof box, or closed iron container.

It is worth remembering that any deviations from the above parameters lead to a drop in current output, a decrease in capacity, or even failure of the battery.

Progress is moving forward, and to replace the traditionally used NiCd (nickel-cadmium) and NiMh (nickel-metal hydride) we have the opportunity to use lithium batteries. With a comparable weight of one element, they have greater, compared to NiCd and NiMH capacity In addition, their element voltage is three times higher - 3.6V/element instead of 1.2V. So for most drives, a battery of two or three cells is sufficient.

Among lithium batteries, there are two main types - lithium-ion (Li-Ion) and lithium polymer (LiPo, Li-Po or Li-Pol). The difference between them is the type of electrolyte used. In the case of LiIon, this is a gel electrolyte; in the case of LiPo, it is a special polymer saturated with a lithium-containing solution. But for use in drive power plants, lithium-polymer batteries are most widely used, so in the future we will talk about them. However, the strict division here is very arbitrary, since both types differ mainly in the electrolyte used, and everything that will be said about lithium-polymer batteries almost fully applies to lithium-ion batteries (charge, discharge, operating features, safety precautions ).
From a practical point of view, our only concern is that lithium polymer batteries currently provide higher discharge currents. Therefore, in the airsoft market, they are mainly offered as a source of energy for electric drive motors.

The lithium polymer battery (Li-pol or Li-polymer) is a more advanced design of the lithium-ion battery. A polymer material with inclusions of a gel-like lithium-conducting filler is used as an electrolyte. Used in mobile phones, digital equipment, etc.
Conventional household lithium-polymer batteries are not capable of delivering high current, but there are special power lithium-polymer batteries that can deliver current 10 and even 45 times the numerical value of the capacity. They are widely used as batteries for radio-controlled models, as well as in portable power tools and in some modern electric vehicles.

Advantages
* High density energy per unit volume and mass;
* Low self-discharge;
* Thickness of elements from 1 mm;
* Ability to obtain very flexible forms;
* Slight voltage drop as discharge occurs.

Flaws
* Number of operating cycles 300-500, at discharge currents of 2C until capacity loss of 20% (for comparison: NiCd - 1000 cycles, NiMH - 500, LiFePO4 - 2000).
* Batteries are a fire hazard if overcharged and/or overheated. To combat this phenomenon, all household batteries are equipped with a built-in electronic circuit, which prevents overcharging and overheating due to too intense charging. For the same reason, special charging algorithms (chargers) are required.
*Aging:
Lithium batteries “grow old” even if they are not used, but just sit on the shelf. After 2 years, the battery loses about 20% of its capacity.
Lithium polymer and lithium ion batteries reduce capacity, unlike nickel and nickel-metal hydride, under the influence of charge. The more battery charge, the shorter its service life. It is better to store them charged at 40-50%, and at a temperature of 0-10 degrees.
Deep discharge completely disables lithium ion battery. Optimal conditions storage Li-ion batteries are achieved at 40% charge of the battery capacity. Lithium batteries age, even if they are not used, but simply lie on the shelf. Accordingly, there is no need to buy a battery “in reserve” or get too carried away with “saving” its resource. When purchasing, be sure to look at the production date to know how long this power supply has already been in stock. If more than two years have passed since the date of manufacture, it is better to refrain from purchasing.
Everything that comes before the number 2000 is the name of the manufacturer or trademark.
* 2000 mAh is the battery capacity.
* 2S1P - 2S is the number of batteries in the assembly. Each battery has a voltage of about 3.7 volts, so the voltage of this battery is 7.4 volts. 1P is the number of assemblies. That is, if we take 2 identical batteries, connect them with “insulating tape” and solder the power wires in parallel (plus with plus, and minus with minus), then we will get a doubling of the capacity, such a battery is designated 1000 2S2P and is actually equal in operation to 2000 2S1P. Usually only single assemblies are used, so 1Ps are not spoken or written.
* 20C - maximum discharge current, measured in battery capacities.

To calculate how many amperes a LiPo can deliver when the engine is loaded, you need to multiply the Capacity by the amount of C and divide by 2000 (since the capacity is indicated in milliamps/hours). The maximum current of this battery will be 50 Amps. For 2200 20C - 44 amperes, 1200 30C = 36 Amperes and so on.

Charging LiPo batteries

LiPo batteries are very charge critical and should not be overcharged or they may catch fire.
For charging, you must use special chargers with a balancer (controls the charge of each battery bank separately).
LiPo batteries are charged with a current of 1C (unless otherwise indicated on the battery itself; recently they have appeared with the ability to charge with a current of 2 and 5C). Staff charging current The battery in question is 1 Amp. For a 2200 battery it will be 2.2 amperes, etc.

There is quite a wide variety of chargers for LiPo batteries, but we will focus only on the most “worthy” ones. All chargers listed below charge Li-ion, LiPo, LiFe, NiMh, NiCd, Pb and new standard 123:


Turnigy are charger clones famous brand IMax. The only difference is cheaper production and cheaper electronic components.
The IMaxes themselves are more expensive.
IMAX B6 Charger/Discharger 1-6 Cells (GENUINE)
Genuine IMAX B8+ Charger/Discharger 1-8 Cells
For all chargers except the first one, you will need a power supply. You can use a computer, from a laptop:
12V 5A 110/240V 50/60Hz Power Supply
"On the road" - you can connect the charger to the car battery.
Using the Twin pack charge lead (2 x 3S)6S and Twin pack charge lead (2 x 3S)6S w/ XT60 splitters, you can charge a pair of identical 3S batteries on a charger that supports 6S. With skillful use of hands, such a splitter can be converted to charge a pair of 2S batteries.
A computerized “charger” balances the battery (equalizing the voltage across each battery bank) while charging. Although you can charge 2S batteries without connecting the balancing cable (white connector in the photo), it is strongly recommended to always connect the balancing connector! 3S and large assemblies should only be charged with the balancing cable connected! If you don’t connect and one of the cans picks up more than 4.4 volts, then an unforgettable experience awaits you.fireworks!
You can protect yourself and charge in special packages - they are not flammable and are specially designed to reduce harm in the event of a LiPo battery fire.

We continue the story about charging LiPo batteries.

Usually, about 90% of the battery’s capacity is quickly filled into the battery, and then recharging begins with balancing of the cans. The more charged ones and those that have approached the limit are shunted and the charge goes to the remaining banks. That's why it can charge a pair of 3S batteries as one 6S.

LiPo Operation

It is not recommended to discharge a LiPo battery below 3 volts per cell - it may “die”. For timely warning of discharge, sound indicators are often used:
Hobby King Battery Monitor 2S
When the battery reaches the limit, the indicator begins to beep, at first rarely, then more often.
When the motor consumes more current than the battery can supply, the LiPo tends to swell and “die”. So you need to strictly monitor this! Use wattmeters to monitor:

Battery Monitor 2-6S
It is enough to measure once for each existing spring and just know how many amperes the motor “eats” on a given spring.

There is one more nuance during operation - our battery is 2000mAh 15C (min). In theory, it delivers 30A. Motors typically allow 20% higher than recommended currents.
In reality, maintaining the maximum current output of a battery for a long time is not very good. For example, there are cases when 2200mAh, 20C supplies a current of 44A for only 2-3 minutes, then there is a “drop” in the voltage, although according to calculations it should deliver at least 5 minutes.
So, when choosing a LiPo battery, you need to pay attention to the maximum current declared for the selected motor and take into account the margin.
So, for a motor that “eats” 8-12A, a 1000mAh 20C is quite suitable, but for 16-18A you need to select either one with a higher current output, for example 25-30C, or take a larger capacity battery, for example 1600 20C.
Nano-tech batteries with a current output of 25-50C are now available for sale.

There are several important points in the operation of LiPo batteries that are strongly recommended to be taken into account. We list them in descending order of danger:
1. Charge to a voltage greater than 4.20 volts/cell.
2. Battery short circuit.
3. Discharge with currents exceeding the load capacity or heating the battery above 60°C.
4. Discharge below 3.00 volts/cell.
5. Battery heating above 60°C.
6. Battery depressurization.
7. Storage in a discharged state.

Failure to comply with the first three points leads to a fire, all others - to complete or partial loss of capacity.

From all that has been said, the following conclusions can be drawn:

To avoid a fire, you must have a normal charger and correctly set the number of cans to be charged on it. It is also necessary to use connectors that exclude the possibility short circuit batteries and control the current consumed by the engine at “full throttle”. In addition, it is not recommended to cover the battery in the drive on all sides from the air flow, and if this is not possible, then special channels for cooling should be provided.

In cases where the current consumed by the motor is more than 2C, and the battery in the drive is closed on all sides, after 5-6 minutes of (continuous) operation of the motor, you should stop it, and then pull out and touch the battery to see if it is too hot. The fact is that after heating above a certain temperature (about 70 degrees), a “chain reaction” begins to occur in the battery, turning the energy stored in it into heat and the battery literally spreads, setting fire to everything that can burn.

If you short-circuit an almost discharged battery, then there will be no fire; it will quietly and peacefully “die” due to overdischarge... This leads to the second important rule: monitor the voltage at the end of the battery discharge and be sure to disconnect the battery after use!
If you forget about the connected battery for a day or two, it turns out that you can say goodbye to it - it doesn’t like deep-discharge lithium.

Depressurization is another reason for lithium batteries to fail, since air should not get inside the cell. This can happen if the outer protective package is damaged (the battery is sealed in a package like heat-shrink tubing), as a result of impact or damage with a sharp object, or if the battery terminal is overheated during soldering. Conclusion - do not drop from a great height and solder carefully.

Storage

Based on the manufacturers' recommendations, batteries should be stored in a 50-70% charged state, preferably in a cool place, at temperatures no higher than 20°C. Storing in a discharged state negatively affects service life - like all batteries, lithium-polymer batteries have a small self-discharge.


Storage mode

Using a computerized charger, you can put the LiPo into storage mode, which will bring the battery charge to 3.85V per cell. Fully charged batteries will die if stored for more than 2 months (maybe less). Verified on personal experience. They say that they are also completely discharged, but for a longer period.
Some people store batteries in a plastic suitcase - it's convenient. Someone stores and carries it “in the field” in the above-mentioned bags...
LiPo is an ordinary battery and if you do not short-circuit the contacts and do not penetrate it, it will not cause any problems during storage and transportation.

Preparing LiPo for use

Getting the LiPo ready for use is very easy - just charge it and that's it!
This type of battery does not have a memory effect (no need to discharge before new charger), there is no need to cycle - do charge-discharge cycles before use.
If you are charging “in the field”, then you should look for batteries with accelerated charging; they are labeled Fast charge 2C or 5C, for example the above-mentioned nano-tech ones have 15C per charge. In theory, they can be charged with a current of 33 Amps!
The charger, which has a maximum charging current of 5A, allows you to reduce charging from 50 minutes to 20!

So, let us emphasize once again the most important points related to the use of lithium-polymer batteries:

Use a normal charger.
Use connectors that prevent short-circuiting the battery.
Do not exceed permissible discharge currents.
Monitor the battery temperature when there is no cooling.
Do not discharge the battery below 3V per bank (remember to disconnect the battery after playing!).
Do not subject the battery to shock.

During my active passion for radio-controlled things, I used Turnigy 9x radio equipment, which I powered through lithium polymer battery with low discharge current - unlike model batteries, which produce tens of amperes of current, low-discharge ones are used for regular power supply of all sorts of low-power things.

In general, one time I simply forgot to turn off the remote control and overnight the battery dropped to an unacceptable voltage level:

A voltage of 3.63 Volts is very, VERY low. For example, a similar model battery - it also consists of three series “cans” - produces quite the correct voltage:

It would seem, what is the problem? We connect the battery to the charger and simply charge it. But all smart chargers are called “smart” for a reason: they simply refuse to charge deeply discharged batteries and display the “Low voltage” error:

But why-u-u-u-u?! Lai-lu-la-ah...

The voltage of a lithium polymer battery is no joke!

Let's first deal with tensions. There are three of them.

1. 4.2V- This upper voltage on a fully charged bank (cell). For two cans - 8.4V. For three - 12.6V and beyond. When the upper voltage is reached, the charging process stops. It is impossible to go higher - overcharged batteries boom and explode fervently and with a spark, this is VERY dangerous and cannot be extinguished with water.
2. 3.7V- This Rated voltage on the bank. This is what is indicated on the battery. For two cans - 7.4V. For three - 11.1V and beyond. Remember that this is not full voltage charge, but rather average.
3. 3.0V- This minimum voltage on the bank. Some people take the lower limit as 3.2V, but three volts per cell is generally a super minimum. You can't go lower. Below it will be bad. In my case, 3.6V for three banks is 1.2V for each, that is, significantly less than the superminimum limit.

Deep discharge is very, VERY bad

There is a magical chemistry going on in the battery that allows it to be discharged and recharged. A deep discharge disrupts this chemistry and after a discharge the battery either cannot be charged back at all, or it is impossible to charge back several specific cells, or it is impossible to achieve its former capacity... In general, there will be something “wrong”. What exactly will happen must be clarified in each specific case. Therefore, it is necessary to charge a deeply discharged battery and find out everything.

How to do this if the charger flatly refuses? Let's cheat.

We charge a deeply discharged battery with a smart charger

Intelligent (customizable) charger The battery is connected twice: with a power connector (plus or minus) and a balanced one (the number of contacts depends on the number of cans). Through the power supply, life is poured into the battery, and through the balance, the uniformity of the fill into each jar is controlled.

To fool the charger's intelligence, we connect the damaged battery to the power connector, and the working battery to the balanced one. And everything will be fine, but remember the important points.

1. Measure the voltage on each bank using a multimeter. Mentally number the pins of the balanced connector (for example, 1-2-3-4 for a three-bank connector) and check the voltage on each pair of pins (in my case, 1-2, 2-3, 3-4). Write this information down somewhere.
2. To cheat, you must use a battery of the SAME configuration. If the three-jar (3S) is damaged, then also use 3S to cheat.
3. Set the minimum charge current, no more than 0.5A. I know that the standard charging current for my model battery is 5A, for the victim it is 2.6A. But here you will have to be patient and wait - safety comes first!
4. Regularly check the voltage with a multimeter on each bank during the charging process (as in step 1) - it should not be higher than 4.2V.
5. Stop the fraudulent charging process when each bank reaches a voltage of 3.0-3.2V. From this point on, you can charge the battery as usual.

I already said that after charging there may be “something wrong”. Some bank may not accept a charge - you can figure this out by the fact that the voltage on it will not rise during the charging process. That’s what happened to me: the first two charged normally, but the third didn’t want to charge at all. So the battery had to be disposed of, unfortunately. But if you don't have one deep discharge, then it may be possible to bring the battery back to life completely. It may run out faster than before. But it's better than nothing.