Ok so i have a battery upfront and a yellow top D31A in the trunk. Both hooked up in parallel. Just wondering if it's a good idea to mix batteries, like add a used kinetic hc-600 or just add more yellow tops. I have a Atomic APX12 and a 2200.1 amp pushing it. My stock alternator is only 80Amps. Thinking about getting a soundstream xxx6500 to push the APX12.

 

I'd start with bigger alt. Mixing batteries is not the best but you can get by with them. I'd start with big 3 if not already done then get a bigger alt. 80 amps isn't enough for your 2200.1.

 

bigger alt and big 3 i think you have enough with 2 batteries.

 

Buy another yellow top for the front.

When you mix batteries that have dofferent ESR's they actually kill each other. The bigger difference in ESR the faster they kill each other.

 

This statement is simply not true. Batteries of different capacity charge and discharge proportional to their capacity. The only time one battery in a parallel string will kill the others is if the charging source is removed and one battery has a "shorted cell".

Any (healthy) batteries added to an automotive system will only increase capacity and lower the total ESR.

 

what? i never knew that!! but question how come one of my buddies ended up with a dead batterie about 3month after he put in his second batterie in the trunk... his front batterie i believe was some motormaster thingy and the second one he put in his truck was a kinetik hc2400? do you think it was just bad luck and his older motormaster seen it last day? play also i have about using a regulator inbetween 2 batteries that way you will not run into any problems?? is this true?

 

first, scrap you 80amp alternator b/c that is good for nothing, and it cannot power more than one battery properly, along with your amp.

You need a strong foundation first, and the alternator is not doing it, so get a bigger one, a lot bigger if you want too run 2000 watts RMS all day.

 

Probably yes.
You can use a battery isolator which is just a couple of diodes on a heat sink, but this means your sound system only benefits from one of the batteries.