Switch with 2 bank charger

• I want to power my 12V trolling motor with one deep cycle battery at a time.
• I have two batteries, a dual bank charger, and a 1,2,both,off switch.
• I don't want to have the batteries in parallel. I want them independent, using only one at a time.
• There is not a motor/alternator in the system.

With that said, how do I wire it?

I was planning on:
1) Taking both battery post negatives together to the negative of the trolling motor.
2) Taking the first battery post positive to the #1 input on the switch.
3) Taking the second battery positive to the #2 input on the switch.
4) Taking the positive wire on the trolling motor to the "feeder" (last of the three posts) on the switch.
5) The 2 bank charger has 2 postive and 2 negative outputs which would go directly to the batteries.

So I started doing this and got concerned about the negatives. If the negatives are tied together;
1) Does this affect the 2 bank charger?
2) Does this affect the battery that isn't "switched on" during operation?

Thanks for your help!!!

 

The negatives being common is in fact common.(pardon the pun) The system you discribed should work fine. The multi bank chargers usually allow for a common negative and the positives are isolated so you won't get drain from the none working side.