The icharger steps up the voltage to the load resistor, so you don't need low ohm resistors. But my resistor bank has an RT(total resistance) of 0.5ohms, so I suspect they are 5 100w 3ohm resistors.



5 10ohm resistors in parallel will give a total resistance of 2ohms, which would only put 4.2amp load on a 8.4v battery.

The formula to calculate RT of a parallel circuit is;

1/RT=1/R1+1/R2+1/R3+1/R4+1/R5

So for 10ohm resistors;

1/RT= 1/10+1/10+1/10+1/10+1/10;

1/RT=0.1+0.1+0.1+0.1+0.1;

1/RT=0.5;

RT=1/0.5;

RT=2ohms


Now we use Ohm's law to figure out current;

8.4v/2ohm=4.2amps

Here are some load resistor bank values;

5 10ohm resistors=2ohm
5 5ohm resistors=1ohm
5 4ohm resistors=0.8ohm
5 3ohm resistors=0.6ohm

Hope this helps