This doing my head in

[Claviger]

For some reason data sheets, circuit diagrams, and doing advanced math is all easier for me than sorting this crap out. Go figure...

I have 2 cells that are 2s1p Li Poly cells, so 7.4 volts nominal with both the 7.4v output wires and 3 wire balance plugs on each. I want to connect them in parallel on the main plugs for use to power a custom mod, and on the balance plugs to parallel charge them.

If I do this, can I use a small 1amp balance charger to recharge while they are still inside the mod and connected to pos/neg on the main output wires? Something like this: All-Battery.com: Tenergy TN267 1-4 Cells LiPO LiFe Balance Charger for Airsoft Batteries

All the diagrams for parallel charging I see online have the main output connected to a positive and negative on a charger, and the balance plug also plugged in. From what I understand and my brain (kinda) is digesting, batteries in series should not be simultaneously connected in parallel as it creates a short circuit. So is this safe or is going to create a short?

 

[steved5600]

If you plan on charging in parallel they will be shorted when the charger is in use. When using a balance plug your in series an charging is meant to be done in this case with a 14.8 volt charger from the positive side of the series batteries to the negative side. I suppose you could charge one battery at a time but that would require an extra plug or a selector switch. Even if you could charge the batteries in parallel it would not be the best choice. IME.