battery isolators

if i have two batteries in the car, one in the engine compartment and the other in the cargo area in the back of the car and they are ran in parallel do i have to run an isolator between the two. i havent had any problems with the sound system so far but today i was driving with the volume all the way down and my amp blew. i have inline fuses, two between the batteries and one for each of the power feeds coming out to the amp. none of the fuses are blown but the amp started smoking. any help

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35 Hertz custom car audio and automotive fabrication

wow, thats really strange. what kind of amp was it? are they the same type of battery? you shouldn't need to run a isolator but it cant hurt. ive hooked up two batteries in a car lots of times and never had an amp just blow up on me.

oh, and thanks to the mods for the third star, i just noticed it.

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its a hifonics amp and the batteries are kinetik hc800's.  its weird, did i mention that the gain is almost all the way down because my girl normally drives the car and she cant take the bass. so with the volume all the way down, gain at about 10% the amp blew. no fuses or anything else blew just the amp. im confused...

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35 Hertz custom car audio and automotive fabrication

whatever blew in the amp may not have had anything to do with the power side of the amp. it IS a hifonics amp so some random part may have just gone out and caused a chain reaction inside the amp.

the only thing ive even seen that was close to what happened to you was with an MTX thunder elite amp that just smoked right in front of my eyes for no apparent reason, the car wasn't even on!

how long have you had that amp installed? what is the ohm load of the subs?

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the amp has been hooked up for about two or three weeks now and hasnt exhibited any problems so far. i have turned the gain up to about 85% and the hu volume 80% when i was beating on them and nothing happened. so its just odd that with gain at 10 and volume off something would just smoke out on me.

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35 Hertz custom car audio and automotive fabrication

thats why it makes me lean more towards a factory defect that just took some time to show up as a problem. if you have a warranty with whoever you bought it from i would see if you can swap it out for a different brand of amp. you may have to pay a little more but from my experience, hifonics is junk. let me know what subs you have and what kind of power you are looking for and i will recommend something for you.

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the amp is the hifonics cyclops 4000rms@14.4 and the subs are 2 orion hcca 12" dual 4

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35 Hertz custom car audio and automotive fabrication

well, i dont know how much you spent on that amp or how much you are willing to shell out for a new amp but you can go with a soundstream (not soundstorm) XXX 4000. it'll probably cost you about $600-700. i would have recommended an Autotek Mean Machine 4000 but you probably have your subs wired down to 1 ohm so that killed it. the autotek does 4000w at 2 ohms

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Re the battery isolators, there are many that say isolation is not required (ie, OptimaJim) and that not even battery matching is required (ie, jmelton86).

On other forums that say similar and quote long parallel battery lives, I merely reply that I get at least 6 year if not 8 years from my "cheap" car batteries (therefore THEY must be getting AT LEAST that from their expensive batteries)....
...and I'm sure they'll agree 2 parallel 6 year batteries makes 12 years (OptimaJim probably will).    


But IMO batteries as you describe should NEVER be paralleled unless in use or charging - ie, they should be isolated at other times.

I use a cheap relay to do this. It is controlled by the alternator(regulator)'s charge light circuit (D+ or L).   
It is cheap, expandable, simple. And it overcomes many problems that so-called "smart"(sic){/I] isolators have.
But I've written ad nauseum on that....