Question about amp draw

[silviasol]

Is this correct for amp draw? With 4 batteries will each pack draw 25% of the total amp draw from the motor? Trying to use smaller wiring for my project in my signature.

Also, based on the left side of the picture, if each pack draws 20amp will each wire connecting the cells in series draw 20amp each?

 

[Drunkskunk]

Yes.

In parallel (your left drawing) the Voltage stays the same, and the Amperage is added together.
In series (right side drawing) the Amperage stays the same, and the Voltage is added together.

 

[Hillhater]

I hope you are aware that the "Amp draw" is determined by the load applied (motor resistance etc) to the pack and is not directly a function of the battery specification.
So..if on your two diagrams above, ,.. unless you have something in the circuit to limit the amp draw, the one on the right will try to draw more current if they are connected to similar resistive loads.

 

[silviasol]

Ok that is what I thought.

Yes I know the amp draw is from the motor. I get no more then 50amp draw max so 20ah and 80ah is the wiring size I plan on using, 18awg for the 4 batteries then 12awg for the motor/controller.

 

[Hillhater]

Ok that is what I thought.

Yes I know the amp draw is from the motor. I get no more then 50amp draw max so 20ah and 80ah is the wiring size I plan on using, 18awg for the 4 batteries then 12awg for the motor/controller.

OK, but remember that if you connect the cells in series ( as in your RH layout), to that motor, there will be a 50amp max current through each cell and connecting wire, not the 20a as shown.

 

[Drunkskunk]

Ok that is what I thought.

Yes I know the amp draw is from the motor. I get no more then 50amp draw max so 20ah and 80ah is the wiring size I plan on using, 18awg for the 4 batteries then 12awg for the motor/controller.

while that would technically handle the power, remember that the resistance will be higher. you would be looking at 2 to 3 volts drop at 50amps with those gauges. you would be better off with 10g main wire and 12 individual wire.

 

[silviasol]

Ok that is what I thought.

Yes I know the amp draw is from the motor. I get no more then 50amp draw max so 20ah and 80ah is the wiring size I plan on using, 18awg for the 4 batteries then 12awg for the motor/controller.

while that would technically handle the power, remember that the resistance will be higher. you would be looking at 2 to 3 volts drop at 50amps with those gauges. you would be better off with 10g main wire and 12 individual wire.

I get 25-30amp WOT on flat ground. I am going to test it out and if needed I can easily swap out the wiring again.