Yes and no. The usb charger I have is made to charge 2 in series, although I usually use my Imax B6 for all my batteries. But in addition, I have a pcb installed in my build. I don't think it balances, but it will cut off if the cells go out of balance. They do have pcb's with balancing, though. This one looks to be about as good as it gets, 8A plus balancing for 2S.There are no issue's with charging 2 3.7 Li-on's in series?
Do they both charge equally?