Question about wiring batteries

[rossmacd]

Could I have two batteries, one in the trunk, and one in the engine bay? Here is my thought process. Right now, I have an optima in the trunk, connected to the starter by 00 gauge, with some 2 gauge going from the alternator directly to the battery. Could I run Brailles in both locations, the front connected to the starter, alternator and powercell (I am using ISIS), with the trunk one connected to the trunk powercell, fuel pump, amp, etc? I could use the 2 gauge to connect the two batteries, and only have to run a short length of 00 from the battery to the starter. Is there something that I am missing? If I wire two batteries in parallel, do I have to connect both positives and both negatives, or can I connect the positives and use the chassis ground for both?? If I did that would remove the benefit that I am trying to achieve (only one cable of a thinner gauge, instead of the one huge and one thinner that I am running right now. I have to replace the optima anyway (sitting for 2+ years).



Please let me know if i am missing something here.

[Mudweizer]

Your plan is fine.

[Mudweizer]

Oh, just connect the positives together, leave the negatives to the frame/body.