Mugen starter box question - adding a switch
 

I just got a new Mugen offroad starter box. I'm planning to rewire it with Deans 12 ga. wet noodle wire and use Deans Ultra plugs. I'm going to run a single 4s Lipo in the box.

I have read about people installing a "main" power switch on their starter boxes between the battery and 1st motor.

My question is, would it be better to install the switch on the positive side, between the battery and 1st motor, or on the ground side between the battery and the 1st motor?
Also, does anyone have any input on what type of switch to use? I know voltage and amperage have to be taken into consideration.

Thanks for your help!

The 2 batteries, the 2 motors and the activation switch is one huge serial connection so if you want to make an on/off switch you can place it in every wire you want.

Wise it is to mount it in one of the battery leads to mak the chance of a shortcut by damaged wires less possible.

Any side of the loop will work just fine. Here's a link to a switch, it's rating is 10A, 125V:
http://www.amainhobbies.com/product_...f-Power-Switch

Should I run a relay with the switch? Or, will the Losi switch (in the amain link above)handle the voltage and amperage?

Also, how much tension should I have in the two drive belts?

Thanks for all the help and input!