grounding a second battery

[stevecut]

where do the grounds go with a two battery set up.
I have one battery, positive goes to a battery switch, with accessories Negative goes to the motor ground. I want to add a second battery, there is a post on the battery switch for a second battery but where do I put the ground, for second battery. Does another battery cable go the motor? I want both batteries to seperate but when I put the switch on (both) I want both batteries to get charged.

 

[eurolarva]

Re: grounding a second battery

You should post this question in the electrics, electronics trolling motor forum. You will get a better answer there. My guess is you want the batteries hooked in parallel which will give you 12 volts. A series set up will give you 24 volts. In a parallel set up both negatives are tied together and the positive leads would somehow be switched.

 

[WillyBWright]

Re: grounding a second battery

First, don't switch it with the motor running or you can damage the charging system. You can run a separate negative cable to the motor, but most people put a jumper from - to -. It needs to be the same size as the motor battery cables.