Dead battery!! - Toyota Nation Forum : Toyota Car and Truck Forums

Rdizzle · 08-24-2006, 03:59 PM

Well after going through 5 batteries this year, i have come to you all for help. My car has now died on 6 seperate occasions, all from the battery failing. At fist they fail in a parking lot and i have to jump it, later they start dying in intersections, which sucks if it has never happened to you. It came with an autozone piece of crap first, then various others such as die hard and most recently before the one i currently have, a 13lb race battery. They have all died. I have no speakers, no headunit as of now, i drive only in the day with no lights. What the hell keeps draining my goddamn battery?!!

***Eye8Pussies*** · 08-24-2006, 04:16 PM

have you load tested your alternator?

Rdizzle · 08-24-2006, 04:20 PM

yep, just a couple hours ago when the battery died again. Working fine.

freeyellow2000 · 08-24-2006, 04:57 PM

you need to really check the alternator?, use a volt meter as see how much volts it putting out. maybe u have a short somewhere

Delay_FTB · 08-24-2006, 05:01 PM

Double check all wiring and ground points for the alt. and batt. I had a loose wire that went to my starter I think, or a ground, I don't recall, and my car would die randomly. I thought it was my battery, and upon replacing the battery, found the loose wire and fixed it (though I still needed the new batt. cause I like to leave my stereo on like a dumbass).

***Durrby*** · 08-24-2006, 07:37 PM

My 1 year old Yellowtop died recently. I was really suprised when it did. I just bought a sears one.
Thats a lot of batteries in a short time. Something way wrong, but you already knew that

***toyomoho*** · 08-24-2006, 10:38 PM

Suggest you install a voltmeter in the car to monitor system voltage during driving. There are some that plug into the cigarette lighter. The alternator should kick up the voltage to say 13-14V. Much higher is not necessarily better.

Several possibilities:

The electrical system could have a higher then normal load draining the battery when the engine is off. With engine and all electrical items off, remove the positive battery terminal and insert an ammeter. See what the amp loading is. The load should be very small (clock memory, etc.).

The alternator could have weak output, just barely covering the load, if that. The battery is running in a constant state of undercharge.

The alternator could also be putting out too much charge at a higher voltage and cooking the battery. This will tend boil out the water inside it.

With the engine off, battery voltage should be around 12.8V for a fully charged battery. 12.5V is about 50% charge, 12.2 close to 0% charge.

Vibration can also kill a battery, make sure it is strapped down.

Rdizzle · 08-25-2006, 12:35 AM

I have had a Scangauge for a year now, and one of the readings is set to voltage. Always a constant 14.2 running almost 13 off. ^The two things i am looking at are strapped down and overcooking. I removed the strap when the race battery was in since it no longer fit and never put it back when i went to a larger battery. I will check also and see if the overcharge could be the culprit. Thanks for the input, i'll let you know how it turns out!

Uluacam · 08-25-2006, 01:05 AM

I almost had a dead battery if it wasnt for my battery tester and charger.
I found out that my alternator was the problem.Got one from Ebay and the
problem got fixed and I alsao borrowed my friends battery charger tester.

marc780 · 08-27-2006, 01:56 AM

Friend the others have offered excellent advice, but i think you have something draining your battery that you have not found yet.

Check : trunk light - does it stay on? Hood light, same. Have any aftermarket electronics been installed, radio, cd, alarm. The workmanship on any of these is often dubious, to say it nice. I believe you have a load that wasnt designed in by the geniuses at Toyota.

At worst case, install a battery shut off and use it until a fix appears.

DFBonnett · 08-27-2006, 10:16 AM

Go here....
http://www.autoshop101.com/
Click on Technical Articles
Select "06"
When the PDF comes up, search for "parasitic"
It outlines how to test
FWIW
YMMV

diver9000 · 08-27-2006, 04:03 PM

1. With your car running remove the positive battery cable. If it shuts off your alternator isnt charging. If it runs then the alternator is charging.
2. Check your voltage at high rpms also - if the alternator is going bad you wont know it from checking it at an idle. Check the alternator while the engine is running at about 3000-4000rpms and see what voltage readings you get.
3. Check the battery ground and see it the ground is corroded (turning green). If so replace it with a heavier gauge ground cable from your local auto part store. They are only a couple dollars.
4. Check your engine ground. You should have at least one ground running from the body of the car to somewhere on the engine.
Start with those choices. They are the cheapest and easiest fixes available. I too think you have something draining your battery that was not designed to run in your car. Good Luck.

Mike Gerber · 08-28-2006, 02:19 PM

"1. With your car running remove the positive battery cable. If it shuts off your alternator isnt charging. If it runs then the alternator is charging."

This one is not a good suggestion. It was a viable test back in the days before cars were equiped with sophisticated electronic components. I have done it myself from time to time. The voltage spikes caused by disconnecting and reconnecting a battery cable while the car is running can ruin some of these electronic components. You may get lucky and not ruin anything, but given the cost of these components, I wouldn't take the chance. IMHO.

I too believe you have some kind of a parasitic draw. Do a dark current test with a DVM to varify this. Off the top of my head, I would guess that the dark current draw of our cars should be 20-25 milliamps.

Mike

diver9000 · 08-29-2006, 03:56 PM

Considering that he is having no luck and he is spending lots on batteries anyway....I dont think the car is so sophisticated that it will harm the internal components to check his alternator. If his car is that sophisticated than on the flip side the car should have a fail safe so he cant harm it.

Mike Gerber · 08-29-2006, 04:27 PM

Quote:

Originally Posted by diver9000

Considering that he is having no luck and he is spending lots on batteries anyway....I dont think the car is so sophisticated that it will harm the internal components to check his alternator. If his car is that sophisticated than on the flip side the car should have a fail safe so he cant harm it.

If the car starts, he can check the alternator himself with a DVM. He can also take it to Autozone and they will test it for him for free. Either of these 2 ways to have it tested, there is no risk of harming anything. IMHO.

Mike