Battery Charge Drains Away

Jul 30, 2005 14 Replies

When I park my car for only 5-6 hours, it will start right up again... but if I park for 11-12 hours or more, I find the battery has drained and doesn't have enough charge left to start the car.



It's clear to me that the battery is "losing" its charge while being parked for longer periods -- however, I can't locate the cause. (I have checked dome lights, all interior lights, radio, air conditioner switches, fan switches, door switches, in fact ALL switches in the car, and NOTHING has been left on.)



To verify that "something" is causing the battery's charge to drain away, I disconnected one cable (the positive one) from its post and late at night I touched it to the post. Sure enough, a small spark appeared, indicating that "something" was draining energy from the battery.



Can anyone offer a suggestion? (Could it maybe be a problem in some component, like a Starter Solenoid or a Voltage Regulator, or something similar?)



I know that if I have tests run on this, I could end up having to pay plenty and STILL they might not find the answer, so I am hoping to find a solution here -- and I thank you all in advance for your suggestions.


This is sometimes caused by a diode in the alternator going bad. Most fix it by purchasing a new or rebuilt regulator, as they usually have lots of miles on them anyway when this diode goes. You should also post the make, model, and mileage when you ask as this often helps folks offer advice.

You're right, I forgot all about that. It's a Ford Crown Victoria, about

95,000 miles, and the Alternator has already been replaced once about a year ago, so it's fairly new. But if no better answers are forthcoming, I'll definitely check it out. Thanks.

Not sure if the Crown Victoria's have the same EEC and Fuel pump relay problems that the older Rangers, Broncos and full size trucks had, but this could be a possibility. For $20 Cdn a relay, it wouldn't hurt to try.

Sharky

snipped-for-privacy@nospam.dfgh.net (Polk) wrote in :

I had the same problem years ago with my '65 Mustang. Then one night, as I was walking past the rear of the car I noticed a faint glow from the taillights. I replaced the brake light switch and the problem was solved!

-- Jim

Why screw around replacing parts that everybody suggests simply because they had a certain part go bad on them once? Do some diagnosis first. Put a meter between the battery and the car and you will see the current drain. Then pull individual fuses until the drain quits. That's the circuit that has the parasitic drain. Posts on how to do this are abundant.

The spark is normal. The car has computers and clocks and stuff that run all the time.

However, you do have another current leak someplace, perhaps a light that is left on, a bad voltage regulator or another problem.

Jeff

How old is the battery!

"Put a meter between the battery and the car and you will see the current drain. Then pull individual fuses until the drain quits. That's the circuit that has the parasitic drain. Posts on how to do this are abundant."

Sounds like very good advice, thanks -- although getting to that fuse box is always a struggle. Assuming I do find the right fuse, what then? I will still not know "which" circuit is causing the problem, because my fuse box does not display anything to indicate the circuits. And as for the abundant posts... sorry to be so inexperienced, but what kind of search would I run to find them?

"The spark is normal. The car has computers and clocks and stuff that run all the time.

However, you do have another current leak someplace, perhaps a light that is left on, a bad voltage regulator or another problem.

Jeff"

You have a point -- maybe that spark IS normal. As for a light being left on, I sure haven't been able to find one, although as another gent suggested, I didn't really look closely at the brake light and will do that tonight.

Thanks to all of you for your suggestions. I will investigate each one carefully -- starting with the easiest and cheapest, of course, LOL.

If anyone want to add another thought or suggestion, I'm always of the opinion that one cannot have "too much" information, and would welcome any further ramblings.

Thanks again, all of you.

Polk

I pulled all the fuses in my 99 Windstar in the interior panel and still have test light between positive post and cable well lit. Think I might have a Voltage Regulator problem in my alternator. It puts out about

13.89 volts instead of the 14-15 and the battery charge light remains on. Trouble is when they bench test it at the auto parts store where I bought it they tell me the alternator is okay and diodes are good.

For those who might have a similar problem.... I had a good counterman at the Oreilly auto parts store actually research the required alternator. The one installed by a previous mechanic was the wrong amperage... 110 amps... the vehicle required an 130 amp alternator. Installed and Battery Charge Light is OUT!! Problem Solved!!

My thanks to all for their help... just a quick note to share an AMAZING page which seems to have "all" the answers about batteries, and I believe I have even found mine in here:

formatting link

"" wrote: > When I park my car for only 5-6 hours, it will start right up > again... but > if I park for 11-12 hours or more, I find the battery has > drained and > doesn't have enough charge left to start the car. > > It's clear to me that the battery is "losing" its charge while > being > parked for longer periods -- however, I can't locate the > cause. (I have > checked dome lights, all interior lights, radio, air > conditioner switches, > fan switches, door switches, in fact ALL switches in the car, > and NOTHING > has been left on.) > > To verify that "something" is causing the battery's charge to > drain away, > I disconnected one cable (the positive one) from its post and > late at > night I touched it to the post. Sure enough, a small spark > appeared, > indicating that "something" was draining energy from the > battery. > > Can anyone offer a suggestion? (Could it maybe be a problem > in some > component, like a Starter Solenoid or a Voltage Regulator, or > something > similar?) > > I know that if I have tests run on this, I could end up having > to pay > plenty and STILL they might not find the answer, so I am > hoping to find a > solution here -- and I thank you all in advance for your > suggestions.

go through your car and give all the power switches a wiggle. i have heard of the power seat switches getting stuck on(but not on enough to move the seat) and draining the battery. if its not that take your battery somewhere and have it tested. there are several tests to see if your battery is good or bad.

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