Wiring Gurus? Need advice!

Running dual batteries. Fuse block and accessories wired to the accessory battery. But the ground from the fuse block is ran to my starter battery (out of convenience). Will this drain my start battery when the accessories are sucking the accessory battery? Or should I run the fuse block ground to the accessory battery as well?

 

Not a "Guru", but instinct tells me that NOTHING should be anywhere near the original electrical system.

G.

 

Start battery will only drain if the positives are connected.

 

Yeah, makes sense the more I think about it. I’ll most likely end up running a separate ground to the accessory battery and leave the start battery factory

 

Spent a pretty penny on Northstar AGM batteries and I want to make sure I maximize the efficiency. Thanks, man

 

It's the same shit. If it's grounded to battery or frame, they're still both connected.

 

Do this instead. It's not absolutely necessary but a lot of grounding issues can be avoided by having ground returns to a common buss connected to battery neg. Don't forget a high current breaker for the main auxilary fuse panel.

 

The grounds are but each battery powers separate systems. Unless the two positives get connected using one system won't drain the other.

 

I have the breakers and an isolator... just was curious if the start battery could somehow drain through the Neg terminal as the accessories pull power from the acc. Batt

 

Thanks

 

If you charge the second battery from your alternator then the positives are connected. If you want to avoid overdischarge of the start battery install an isolator switch to separate the systems when parked and using auxilary power. Edit-just saw your last post -you should be gtg then.

 

Yap.

 

Seems like everything is wired up correctly. I would just make sure both negatives have an independent wire going back to chassis.

 

Never even thought about adding a ground to chassis on the accessory battery. Thanks! Right now the ground is going back to the isolator