How to charge a RC LiPo battery

Today, Lipo batteries have been widely used in our daily work, and how to charge it safely?

1. Choose a charger

There are many charger options on the market, from cheap AC wall devices priced at $ 20 to high-current, multi-output chargers that cost hundreds of dollars.

All decent chargers are equipped with built-in balanced ports. In fact, many of the cheapest chargers on the market contain only one balanced port. These chargers are really nothing more than toy quadcopter chargers, and only need to charge each battery individually. If you have a certain amount of hobby accumulation, it is best to choose a more advanced charger.

Of course, whether you use a high-level charger or a normal charger, they almost all have the same computerized interface.

2. Charging process

First and foremost, you must use a LiPo charger to charge LiPo batteries. But most LiPo battery chargers can charge many  different types of batteries. If you use it, please 100% ensure that you will never use the charger to charge LiPo batteries in non-LiPo mode. This may cause failure and fire.

The charging speed of LiPo batteries is different from almost all other batteries on the market. Apply a constant voltage slightly higher than the current battery current to the battery terminals. Current flows through the battery and the charging process begins. This current must be adjusted by the charger to avoid oversaturation of the battery. Once the battery reaches the set voltage, the current will slow down and eventually stop. LiPo batteries will not "trickle charge", and there is no safe saturation point, such as car batteries, they will no longer accept charging. If you overcharge the LiPo battery, it will eventually explode.

This is the most important thing when charging LiPo batteries-if you try to charge it at any time, they will accept the charge, slowly increase, and eventually explode in a huge fireball. This is also a huge difference between LiPo batteries and other chemicals. If you insert a LiPo battery into a car battery charger or NiMH or NiCd charger, it is likely to explode.

Generally, computerized chargers can use a series of modes: charging, fast charging and balanced charging.

It is recommended to use balanced charging. Then, select the number of amplifiers and the number of batteries to be charged.

Take care to ensure that the correct cell count is selected! Although most chargers will issue a warning before you try to charge a mismatched battery.

Most chargers also have some built-in security checks. these are:

• *The confirmation screen before charging starts asking you to confirm the number of batteries.
• *If the battery is not detected, the automatic charging is canceled (when balancing charging).
• *If the battery voltage exceeds the specification (in case of balanced charging), the charging will be cancelled automatically.

As you can see from the above, you can get the most built-in protection when charging in balanced mode. For this reason, it is recommended to charge the battery in a balanced mode as much as possible, and do not risk using other modes unless professionally instructed.

So, how to judge whether the battery is in a balanced charge state?

On most chargers, when the word “BALANCE” is displayed on the charger screen, you can only charge the balance charge. If you see "CHARGE", it means that you are in "normal" charging mode, even if you plug in the power supply, the balance tap of the battery will be ignored.

As for the amplifier, the Ah rating of the battery will help you determine the number of amplifiers to be charged. The amplifier you choose here is the speed at which current flows into the battery.

Usually, you want to charge the battery at 1C, or the same as the mAh rating of the battery. Therefore, if you have a 1.3 Ah battery pack, charging at 1.3 amps is considered 1C charging.

Some batteries are rated to charge faster (2C or even faster), but usually faster charging means you may shorten the life of the battery.

If you think there is a problem with the battery, you can charge it at 0.1C, for example, in the case of 1.3 batteries, it is 0.1 or 0.2 amps. It is better to ensure safety first rather than speed! Of course, it is best to replace with a new battery.

3. Charging safety

*When charging lithium batteries, try to avoid using flammable materials. You can charge in a metal box so that it can contain flames in the event of a fire. Some people also put a bag of sand on the top of the charging case to prevent the battery from catching fire. The fire will burn a hole in the bag, and the sand will fall on the flame and extinguish.

*As long as your battery is not physically damaged and the battery is balanced, you can safely charge it. However, it is recommended to take preventive measures.

The most important precaution you can take is not to charge unattended batteries. If something happens, you must be able to react quickly. .

*Before charging, please check each cell of the battery to ensure that it is balanced with the rest of the battery pack.

You also need to check whether the battery is swollen or damaged. If so, it is best not to recharge and buy a new one.

*In the charging process,don’t leave

The first line of defense for charging is to place it where you can watch it. This is especially important if you are charging the battery indoors. When charging the battery, never leave your house unattended. If the area where you charge the battery has any flammability, you should not even leave the room. Either way, make sure there is a fire alarm in the room you are charging.

How do you know what went wrong?

LiPo batteries that are overcharged or damaged and ready to explode will first expand in size, called "swelling." This process will emit odor. If you see that the battery is performing this operation, immediately pull it out and throw it outdoors where it will not cause danger. It should be kept in a safe place for several hours, and then discharged and treated by putting it in saline solution.

*Battery container

Putting the battery into a fireproof container during charging is a reasonable step to prevent or reduce damage in the event of an accident. No matter which container you decide to use-make sure you never seal the battery in a sealed container. When LiPo batteries are "off", they will release pressure and heat. If sealed, it may be enough to make a bomb.

*LiPo bags

Some manufacturers have introduced fireproof bags for charging batteries. When these bags work, they contain any flames caused by the explosion. However, please note that these fire bags are currently unable to confirm which ones are effective and which are not. So try not to take risks.

*Bricks

If you have ambitions, you can go to your local hardware supply store and buy some bricks or cinder blocks to build a fireproof “house” for your LiPo battery.

In order to ensure the safety of charging, it is necessary to develop some good charging habits

•  Make sure the charger is in "LiPo" mode.
•  Verify that the battery charge rate is accurate. To do this, please divide the mAh value of the battery by 1000. The 1300mAh battery pack should be charged to 1.3A.
• *After starting charging, check the series mode again and count again.
•  Verify that the charger is in unit count mode (eg 3S, 4S, etc.)
• *Cross-check the number of batteries by physically viewing the battery or balancing the connector.

Conclusion:

Lipo charging is very safe, as long as you follow the guidelines, use common sense, and don't take risks. A good battery can last for hundreds of cycles before charging.