Some driving/after pics:
Boy drive with 2* 8.4v/4000mah & 2* 7.2v/4000mah nimh, because lack of lipo cut-off.
I'm using 2s/4000mah lipos.
Here is my charger:
I can charge all four batterys at same time, it takes about 25min (all four empty batterys to fully charged).