Rules for adding second battery

[reclessantics 10+ year member]

That's kind of a dividing point for the forum. A lot of people swear they have to be the exact same batteries, other say it doesn't matter, and others say you have to use an isolator. Personally I've never had a problem running different batteries together with no isolator. It's been said that doing this will shorten the life of the batteries because they will have different resting voltages and will always be trying to equalize the system and drain each other. If your talking about buying new batts, and just getting two different physical sizes but the same style battery I think you'll be fine.

yeah i mean, i always here this. lol hmm. part of me wants to just go with a normal (stock size) d3400 batt under hood, and then slap a d 3100 in the back. im not really sure what the biggest size is that i can squeeze under the hood yet. but i mean the battery isolator is probably going to be my last option. was going to run say 2 runs of 0ga pos and neg from front batt to back batt either way. (4 runs total)

but im really feeling getting a new alt and big under hood battery right away. lol kinda turned on to doing some electrical work now that i have some flow

 

[reclessantics 10+ year member]

Just looked at some old messages from MECHMAN. and he was telling me, not to hassle with trying to sqeeze anything bigger then the d3400 under the hood. get that and i told him i was looking for an alt anyways. and just go with that combo at first, and see how it works then get another battery, (d3100 is what we talked about putting back tghere) later to tweet the system and what not.

so i think thats how im going to do it. and i dont want to get a small h/o alt, id rather just get one big heavy duty one, that isn't going to be running at 100% so it'll last, and i wont have to upgrade later.