Originally Posted by Greebe
Tram what packs would you like to charge simutaneously with the 109?
As long as they are of the same capacity and cell count (albiet balanced and in similar good condition) it can (read: 2/ 3s packs used in a 3S2P config discharged together). Just use a parallel Y cable to hook up...
The packs I've made have taps so I can balance cell by cell. This comes in handy only if there is questionable performance related issues where none existed before.
If they are not of the same discharged cpacity then it would be best to charge seperately... but if close simply adding a high wattage 0.1 ohm resistor to each pack Y leg will help balance the current load between packs. Also need to monitor each packs voltage (eg using 1 DMM per pack or similar).
This is where Suzanne's cell balancers would really come in handy.
Warning: You must babysit them (watch them like a hawk) at all times when doing this.
I have 3 packs for my foamy planes. They are the same capacity 1500mAh, countcell 3S, brand, and date of manufacture. But they are used in a different power setup, so they are at the different charge condition at the end of the fight.
Can I discharge one by one pack with AstroFlight 109 charger disconnecting them at the point when charger reports they are discharged. By such procedure I should rech each pack to be at barrely the same condition. Then let them rest for 10 minutes. Then using parallel Y cable to connect them to make 3S3P and charge them with 4.5A.
Can I do this? Is it safe? Will I damage the packs?