battery isolator...

[KyleBechtold 5,000+ posts]

Ok so looked through a few threads and couldn't get a definitive answer..

I have an interstate battery up front and an hc2400 in the rear.. a 200amp alt.. do i need an isolator? I am thinking i do.. but just wanted to check.. These aren't hooked up yet so idk the results yet

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[Papermaker85 5,000+ posts]

Ok so looked through a few threads and couldn't get a definitive answer..
I have an interstate battery up front and an hc2400 in the rear.. a 200amp alt.. do i need an isolator? I am thinking i do.. but just wanted to check.. These aren't hooked up yet so idk the results yet

waste of money, just use the apporate wire between batteries both working in conjunction will help stablize voltage under highly dynamic loads..

 

[DidUHearThat? 10+ year member]

Please put a fuse (rated to the wire) within 12" of each battery on the wire connecting them.

If you don't leave your car parked for more than a couple of days at a time or listen to your sound system with the engine off then you don't need an isolator. If you do either of those things you should have an isolator.

 

[KyleBechtold 5,000+ posts]

Please put a fuse (rated to the wire) within 12" of each battery on the wire connecting them.If you don't leave your car parked for more than a couple of days at a time or listen to your sound system with the engine off then you don't need an isolator. If you do either of those things you should have an isolator.

I will soon but i will disconnect the back battery before i leave.. an i will obviously have the proper fuse..

 

[gotparts90 10+ year member]

most people say no but the engineers at Johnson controls (makers of about 30-50percent of all batts) where I used to work told me use one if the batts are not the same down to lot number and manufacture date. the low one will draw from the high one when it is off. but do whatever you want its your money

 

[DidUHearThat? 10+ year member]

I will soon but i will disconnect the back battery before i leave.. an i will obviously have the proper fuse..

I bought a high current battery switch, but I haven't installed it.

That's TWO fuses. One near each batt. Otherwise if, for example, where the cable goes thru the fire wall the sheet metal rubs a cut thru the jacket and shorts the wire; both batts are now shorted to ground. If you have only one fuse, that fuse will pop, but the other battery is still shorted to ground and the wire between the fire wall and that batt will get red hot and set your car on fire.

If there are two fuses inbeteen then they will both pop and the wire is dead.

Fuses are cheap.

 

[audioholic 5,000+ posts]

waste of money, just use the apporate wire between batteries both working in conjunction will help stablize voltage under highly dynamic loads..

Isolators and relays are a waste of money? Maybe if you do not understand what they do.
For example, if you have a nice new batt in the back for your stereo, and the old stocker up front for the engine, simply running the 'appropriate sized wire' between them will not keep you from having problems.

Another example is the guy who likes to run his stereo with the engine off, but doesn't like stranding himself with a dead battery at the end of the day.

To the OP, if you run multiple batts, remember that you need a fuse at BOTH ends of the wire. With batts at both ends of the wire, a short could draw power from either direction in the wire. Im always amazed how many people dont realize this when they install mult batts. Very dangerous.