Here's the deal. I go to my car after work and it's dead. I get it jump started, and drive home. An hour later, car can't start again. Took the car to sears and they said it's the battery, so I get a new one. Drive it home, it's fine. But I start it up again and notice that when I have my lights on, I can hear the idle drop. Now if I already have a new battery, could this be the alternator that is the problem?

The battery that I originally had in the car was an Optima yellow top. The battery is only 9 months old. So I replaced it with a new Optima. But if I'm still getting dimming lights, etc., what could be the problem???

Also, I have 2 amps which are pushing a little less than 700 watts. Hard to say if this is so.

But due to the constant drain on the battery, could it be the alternator too?? Is the stock Honda alternator not capable of charging the Optima fully, etc.??? Can someone please help and give me some thoughts?

 

Do you have a cap with your stereo? 2 amp is a bit of a drain with no stiffening capacitor

 

Nope, I don't have a cap. Would that help at all? I've been told that I didn't need one and that a cap really won't help?? I have no clue on this though, I'm not an expert at car audio at all.

 

you may have a parasitic drain on your electrical system...Are your amps staying on continuously even w/ the key off?

Check voltage at the battery with the engine running with all electrical loads on. Should get about 14.5 volts.
If you can test for current draw, your car should not draw more than a couple miliamps (.005A) when the key is off...
Autozone can check your alternator for free!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PyroProblem &raquo;</TD></TR><TR><TD CLASS="quote">...
Autozone can check your alternator for free!!</TD></TR></TABLE>You can do a reasonable check yourself, too.

Start the engine, let it idle, extra electrical stuff turned off. You should measure about 14.5v at the battery.

Now turn on everything you can. All your lights, blowers, wipers, amps, defogger, whatever. How much does the voltage drop? (Shouldn't be much...)

 

I have an even easier test. Start your car and let it run for a bit with everything electircal turned off. Then disconnect the negative battery cable. If your car dies immediately you need a new alternator. Or something is drawing current like crazy. You need to have the current measured when the car is off. If it's more than a few amps (that's electrical current not stereo equipment) then something is wrong. Either a short or your stereo isn't wired right.

(I saw 2 amps and thought you meant current )

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Raven18940 &raquo;</TD></TR><TR><TD CLASS="quote">I have an even easier test. Start your car and let it run for a bit with everything electircal turned off. Then disconnect the negative battery cable. If your car dies immediately you need a new alternator. Or something is drawing current like crazy. You need to have the current measured when the car is off. If it's more than a few amps (that's electrical current not stereo equipment) then something is wrong. Either a short or your stereo isn't wired right.

(I saw 2 amps and thought you meant current )</TD></TR></TABLE>

DO NOT DISCONNECT THE BATTERY CABLE TO CHECK CHARGING SYSTEM.
the alternator needs a voltage reference to charge correctly if it loses that reference some times it goes to charging more than 14 volts. It can burn up electronics.

 

*shrugs* My bad. I never had a problem with it, but it is a trick I learned on american cars. Maybe these jap cars are more sensitive. Anyway it's only for a moment, don't leave it like that.

Sorry.

 

no problem. We had a customer do that on an old dodge truck.. It burnt the cluster up inth dash and blowed the headlight bulbs..

 

Took it to Sears, I know it's not the best place. They tested it and replaced my battery with a new yellow top Optima. The car starts fine. Let it sit overnight and started it this morning with no problem when it was cold (for Hawaii) which is around 63 degrees or so. Question is, when my turn signals are on, the gear indicator light dims a little. I've never noticed this before, or I could be just noticing it now. But I don't believe that I've seen this happen.

So given that I have a new battery in the car, shall I tell Sears to isolate this even more and dig into seeing if its the alternator now?