(To see a list of all my Quadcopter blogs, click here).
I’m about ready to apply power to the quadcopter to start programming the flight controller. But before I can do that, I need to have a fully charged battery.
My quadcopter (and I’m guessing pretty much all of them) uses a Lithium battery, LiPo (lithium polymer). They can produce a lot of power for their weight. No surprise Lithium batteries are in the new Boeing 787. And if you haven’t heard about the lithium battery fires on the 787, well, you have to be a bit careful with these batteries because they can catch fire and explode.
So today I sat down to figure out how to correctly and safely charge the two LiPo batteries I purchased for the quadcopter.
Let me start by saying in my research one person recommended charging LiPo batteries in a fireproof bag like this:
I don’t know about that yet. I’m all for safety, but I don’t put my laptop batteries in a bag. Then again, they have a dedicated charger so there should be little room for mistakes. So I guess the take away is if you don’t use a fireproof bag, MAKE SURE the charge settings are correct.
I purchased Turnigy 2.2A batteries:
and the Turnigy Accucell-6 battery charger:
The first thing I noticed on opening the battery charger box is there is no A/C transformer. CRAP! Don’t tell me I’m going to have to order something else and wait!
No, no, it’s all cool. This video talks about various options for providing the input power:
I have a computer power supply converted to a bench power supply. I just connect the alligator clips to the +12V banana plugs:
I then used this video to set the charger up:
Following those instructions I had the charger up and running quickly:
Here is the basic procedure
- Connect Banana plugs to 12V power
- Plug Battery’s balance lead into charger
- Plug Battery’s power lead into charger
- Turn on power to charger
- Press Type until LiPo BATT is selected
- Press Start/Enter
- Press + until LiPo BALANCE is indicated
- Press Enter for Amperage to flash
- Press +/- to get charge rate set at 2.0A for my 2.2 turnigy batt
- Press Enter for Voltage to flash
- Set that to 11.1V and press enter
- Press and Hold start until it does battery check.
- Verify R: 3SER S: 3SER
- Press Enter to start charging
The first battery charged in roughly half an hour and I checked it frequently for heat but it remained cool. You can purchase this temp sensor to place on the battery while it is charging to kill the charger if the battery gets hot:
Jul 6 2014 Follow Up:
I don’t know how I missed this during the initial research, but my 2200mAh batteries can be charged with more than 2 amps.
If you look at your batteries’ specs you will see a charging “C” value. In the case of my 2200mAh batteries, the charging C value is 4. That means the battery can be charged at a rate 4X it’s mAh rating (2200mAh or 2.2Ah). 4×2.2 = 8.8A as a maximum charging rate.
My charger can only charge at 6A, but that is still a lot faster than 2A would be.
I set the charger for 6A. Even then it only charges at 4.2A because it has a max rating of 50W. I did watch the first couple of charges at 6A (really 4.2A) and the battery stayed cool during the process.
My new 5000mAh battery is rated at 2C. That means I could charge it at 10A should I get a charger capable of that.
Here is a great article on LiPo batteries: