Originally Posted by
diff_lock2
You can charge the packs it series if the charger can handle the large amount of cells. Mine can do up to 14cells so 2 6cell packs in series is just fine, and act like one 12cell pack when charging and discharging. You should not charge ni chemistry cells in parallel since you can end up with totally unbalanced cells.
I have charged packs in parallel in the past without issues. I did use them in parallel, however, and didn't use packs that had been charged separately. My thoughts on it at the time was that I didn't want to run unbalanced packs connected in parallel. However, I now charge the 14.4 packs as a single unit, i.e. 2 packs in series. I haven't had any problems with my charger or the packs.