[bigred5765]

i have a skyrc 800 watt duo charger that can charge at 20 amps ether side
and a1200watt power supply Ive tried charging at 10 and 20 amp works just fine
also you don't need as big a power supply as you may think at 10 amps per side my power supply was show less than a 12 amp draw on it at 15 volts
to work out how many watts you need is a simple sum
volts 7.4 x amps 10 = 74 watts even at full voltage thats only 84watts
to charge 8.4 volts at 20 amps you would need a no more than a 270 watt power supply