Battery Drain

I've had my system in my Civic for about 6 months. A few days ago I started getting the dreaded alternator whine, but only in the front left tweet( I have seperates). It's not consistent, sometimes it's not there, sometimes it's loud, sometimes not...After about 3-4 days of that the battery is now draining over night. I haven't checked yet to see if the amps are turning off when they should. Does the alt whine and draining batt have anything to do with each other? Thanks!

2000 watts(two monoblocks and one four channel). Another tid bit of info...this being the holidays, the car had sat unused for about 3-4 days when the dead batt problem arose. Before that everthing was fine, minus the alt noise.

sorry, forgot one thing. The car is a '03 Civic, I bought it off the lot almost exactly one year ago. I have two batteries, the stock starter batt and a yellow top wired in parallel. Both are getting drained.

dkiley wrote: sorry, forgot one thing. The car is a '03 Civic, I bought it off the lot almost exactly one year ago. I have two batteries, the stock starter batt and a yellow top wired in parallel. Both are getting drained.

Yep, if they're wired in parallel without diodes or another type of battery isolator, they'll both drain down (or fail to charge, depending on what the problem is).  The batteries have gone dead more than once, right?  I mean, the first time you found the car dead, you got it started, drove it around, and then it did it again the next time you parked it, right?  This is sounding more and more like an alternator issue.

Scott Gardner

check you battery just had a problem in a civic myself, your water levels might be low,    also these cars really need to be regrounded at the head unit the factory ground sucks. also look at putting a noise blocker in line with your power2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

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Do you have a battery isolator between those two batteries? If not, that could be another issue for you to look into.

Well I seem to have eliminated one thing. I jumped the car, it started, and then took the + lead off the starter battery, the car still idled fine. I hooked the + back up and drove it about 60 miles today, that should mean the alternator is fine. Incidently, before I jumped it and drove for awhile, I pulled the main fuse between the starter batt and all the amps. No more drain. It's got to be a short somewhere with the amps. Now comes the multimeter. I don't have a battery isolator, my local install shop and the local Autozone told me to just run the batts in parallel and be done with it...so I did. As far as the HU ground, I grounded it to part of the underside metal dash...

dkiley wrote: the stock starter batt and a yellow top wired in parallel. Both are getting drained.

The first problem you have is the fact you have broken golden rule number one. Both batteries MUST be of the same age, capacity, and AH. The second rule is installing a battery isolater. So as the SLI battery can do what it is intended for. That being to allow your vehicle to start. While the other one will allow you to listen to the music while the vehicle is off, without fear of draining the primary battery. The third is the fact that your alternator, as it was stated by Durwood, is too small to meet the current demands you have laid out. I have yet to be in any Honda / Acura where the maker has actually installed an alternator of appropiate size with enough reserve to supply a simple third party device such as an amp, for long term use. Perhaps one day, they will actually use all that knowledge in that skull and take a page from the domestic guys and supply a 150 amp alt, off the bat. The forth problem is the stop and go driving you are doing. If your vehicle is going to be sitting around for any period of time, and you are ground pounding, like most are. You will have to use a battery maintainer to restore the loss of voltage / current. Just so you know, everytime you allow a standard wet cell SLI battery run down to 11.90 VDC, that is almost 25% depletion... You have taken off 30% of the battery service life out of the battery. When you go down to what ever auto shop you feel can do the job right. Have them do a standard AVR test, which includes reading the specific gravity & using a conductance meter. This will tell you 100% as to the state of charge, and service life you will have for the primary battery. The yellow top is a sealed AGM, and cannot be refilled, but is capable of handling over 300+ cycles of depeletions to 35% capacity. Keep your eye on that primary battery, and have them varify the state of the alternators diode packs while you are there. Regards EVIL Teken . . .