I have buying and using the traxxas lipo batteries with much success. I have 4 now,a 3s 8400,a 3s 4000 and a pair of 2s 7600s.
The only issues I have is with charging. The balance board on my charger is short as well as the ones on the battery. The main charge lead is plenty long enough to get deep down in my lipo sack but with the balance taps plugged in I can barely get them in the bag.
Does Traxxas or anyone make a JST-XH (electrifly, traxxas, ect) M to F extention for 2s, 3s balance taps?
Also I have been reading about a 2x2s to 4s tap coverted that would allow me charge and balance My 2s 7600s in series. My charger will only go 8 amps but up to 6s. I read in a magazine article that traxxas is making some kind of adaptor that will allow charging dual 2s or 3s packs with thier new lipo charger. Maybe in series or parallel.