How to charge two, two cell packs in a plane.

[jhelber08]

Thanks for all the responses from everbody. The batteries are connected in series and the charger will see the terminal voltage at 16.8 volts max. (4.2 Volts/cell fully charged. ) The "Y" is connected the same way as a four battery pack would be. Yes I agree that a second charger will do the trick and avoid any possible connection errors. Yes again at home all my batteries are balanced and brought back to storage charge ready for the next flying day. Yes to the connection between the packs while charging through the balance port the packs need to disconnect from all the switches in the plane. That one I missed. Yes that will give you a ground error. Ok will not do this.
Ok can we take this one step further as a technical discussion. the two pack are removed from the plane they are on the work bench they have both been balanced and have about the same charge, the main power leads are not connected. Like to charge as shown in sketch. WHY WILL THIS NOT WORK.

So your saying you tried it and it doesn't work or are you just asking? I think it will work. Only thing I can think though is that you still need to use a series connector to tie your two discharge cables on each battery together or just use the (+) from pack 1 and the (-) from pack 2 to connect to your main charge lead. Essentially all you've done there is make a 4 cell battery pack.

 

[ThePledge]

There are a ton of diagrams for both serial and parallel charging out there on google. If you have any doubt about soldering up your own harness purchase this: http://www.buddyrc.com/2s-xh-twins-charge-adapter.html

The charger will see it as a single 4s pack because it will be wired exactly like a single 4s pack. It's no more dangerous than charging a single 4s pack because again, wired exactly the same.

 

[Dan767]

Charge them in parallel. Get a parallel charge board from Progressive RC . Fairly certain that they work with your charger.

 

[Snoopy1]

This FMA charger only charges through the balance connection at a max of 4 amps. No I agree with you guys but you know how sometimes you are sitting around home and you think of these things but the ground fault from the connection was enough for me to stick to charging the normal way. Just as said Terry the risk is to high to make a mistake at the field when you talking to people and not concentrating on the batteries. Just out of interest I did try it on the bench and it did work.

 

[Snoopy1]

Yes Dan 767 you are correct I can and do normally parallel charge them.