Ok ive got door poppers and sometimes they need an extra kick ive already got a red top dry cell in the car and that isnt enough I have another red top just sitting around and want to throw that in and wire them in parallel. does anyone know if I can do this without causing damage to the starter? the combined CCA of both batteries would be 1440amps @ 12 volts. I also have an incar computer so I was planning on having two batteries anyway.

 

I am no expert, but I woudnt think it would be much of an issue. Just because it is avaible, doesnt mean your starter will use all of it. your starter will get the voltage, suck the amperage it needs, and thats all. Wire it up, put a big huge relay on the connection cables, run a switch, and see what happens!

 

I would say you'll be ok, it's done all the time in trucks and off-road vehicles. Just make sure everything is wired safely.

 

at 12v, your starter will see the same amount of current, no matter how many batteries you have. you wont need any fancy electronics, just some extra wire. you engineers always think too deep into stuff and forget the basics.

 

thats what i was saying... but i was saying if you wanted to put a relay in there, so when you turn off the car, one battery isnt trying to charge another, there shouldnt be anything wrong with that.. otherwise, there really wont be any issue

 

Diesel trucks run multiple batteries without isolators. The only reason you would need an isolator if if the two batteries run seperate electrcal systems. Example; One runs the car and the other runs the stereo. The isolator would allow you to run one battery completely dead and not effect the other at all.

But... If your door poppers aren't getting enough current it's because the wires are too small. Based on the length and size a wire can only more so much current. Adding another battery will not change that.

 

duh.. i completely looked past that one too.... yah, if you know for a fact your poppers arent getting enough, check your wiring.. also, check your battery voltage when everthing is off. if it is at like 11, you need a new battery. that might make them not function properly either.