Quadcopters and Drones use LiPo batteries. Like the multicopters they are used in, these things are serious things that you must not mess around with.
The fact that none of this information is easy to come by, to me, is rather mind-boggling. Go to youtube and search for “lipo battery”. Before you finish typing, the auto-complete gives you a good idea of what I’m talking about:
True, most of these videos appear to be teenage boys doing what they do best, namely, damaging things and setting them on fire. However, it does show that these batteries can be dangerous. Lipo batteries didn’t exist when I was young, and we had to set fire to other things. It’s a fact that Lipo batteries can reach a state when damaged and overcharged, that they can explode in a large fireball.
So, there are just a few things to keep in mind, and you don’t have to worry too much about these things.
Note: these things apply only to LiPo batteries.
Don’t leave them charging unattended
Look, it’s simple. There is an non-zero chance that these things will turn into a large fireball. Treat them that way. Do not leave them charging and then leave the house. Don’t leave them charging and then go to bed. Don’t do it.
Lipo Batteries are a bit fragile
Don’t drop them too much – that’s how they get damaged. Lipo batteries are basically a thin layer of chemicals in between two pieces of foil, folded up in an accordion shape. It’s possible that it could get damaged on the inside without being visible to you. Treat them gently.
Don’t discharge them completely
If a LiPo battery reaches 0% charge, you won’t be able to charge it again – it will be dead, and there will be nothing you can do about it. Most devices that use LiPo batteries therefore shut themselves off before the batteries reach a certain voltage.
Faster charge = shorter life
If you always charge your batteries as quickly as possible, they won’t live as long (in terms of charge cycles) than if you charge them more slowly. A good rule of thumb is to charge them with as much current as the battery capacity. So if your battery has a 2200mAh capacity, you’re safe to charge the battery with 2200mA of current, and your battery should last a good long time. A lot of these kinds of batteries are not very expensive, so for some people it’s preferable to charge them with the maximum current they can handle, and replace them whenever they wear out. That’s ok too. But for a flying machine, you don’t want any surprises, and it’s good to have batteries that last for a reliably consistent amount of time.
Use a charging bag or metal container
The most likely time a LiPo battery will explode is when something goes wrong during charging. Therefore, it is a VERY good idea to use either a charging bag (you can get them smaller or bigger of course)
There is no memory effect
Nickel Cadmium (NiCad) batteries did have a memory effect – you had to discharge them all the way, and then charge them completely, or they would lose their power. But no one uses this kind of battery anyore. LiPo batteries do not have a memory effect. In fact, they wear out faster if you discharge them more, and charge them to 100% capacity. They will last longer if they stay closer to 50% charge, and if they are charged no more than about 80%. (This is why, for example, the batteries in the Tesla Model S are only charged to 80% unless you specifically decide to “top it off” all the way at 100% charge).
Store them long-term at half charge
LiPo batteries don’t like being stored for many months at full charge. If you can remember, it’s a good idea to store them charged only half way, and to charge them a little bit every few months.
Again, this is for LiPo batteries. Lead acid batteries for example (like your car battery) must be stored long-term with a 100% charge.
Use a decent balancing charger
With a good balancing charger, you can be sure that you can do whatever you need to do – maybe you want to charge your battery for long-term storage, maybe you want to charge your battery slower or faster depending on the situation. Here is a good lipo battery charger that can also charge most other types of battery.