Two 12v batteries, one starting battery, one deep cycle for toys/trolling motor/etc.

Is it recommended, not recommended, unnecessary to setup say a ground bar in the console run to both negative battery terminals?

Initially I was going to run a couple devices/switches off the starter battery, then a few more off the secondary battery. However the switch panel comes prewired with a single common ground. I wasn't sure if it was even possible to tie all the ground/negative stuff together.

I've since decided I'm only going to run the starter off the starting battery, everything else off of the secondary, but this question has been bugging me and I can't find a conclusive answer.

Thanks again gents!

Trolling motor should be isolated on it's own circuit, irregardless of the voltage. No common ground between the two. Everything else should run on cranking battery. If you are running high amperage toys, I would consider putting two 12V batteries in parallel for these, but keep the TM separate.

The neg on the TM goes to the TM battery neg post. There should be a red wire from the starting battery that feeds 12V to the console and everything will run off off that. The battery NEGs are not tied together. There is also 12V switched that is fed to the console with the key on to run certain items but don't try to tie into that if you don't know what you are doing.

Thank you, I�ll run a 2nd pos/neg off starter battery to run lights/finder/etc and not feed off ignition pos wire.