Posted By: stumpy
Weird battery problem - 02/01/09 08:03 PM
My battery will go dead sitting for 3 days but it passed a load test. No system draw. If I drive every day the battery will start the car. Is it possible that even though it passed a load test it could still be bad.
Posted By: Dodgem
Re: Weird battery problem - 02/01/09 08:30 PM
If you unhook the battery cables when fully charged does it still go flat in three days??
Posted By: stumpy
Re: Weird battery problem - 02/01/09 08:37 PM
I trying that now. It shows 12.48v. I'll recheck it tomorrow. I just wonder why it passed the load test.
Posted By: Dodgem
Re: Weird battery problem - 02/01/09 08:55 PM
i don't know but if it's fresh of a charger it should be 12.8 to 13 and fall slightly over night to 12.7 or 12.6 and hold there for weeks??
Posted By: AARCONV
Re: Weird battery problem - 02/01/09 10:05 PM
something is wrong in that mix,u charged it and it passed the load test...let it sit and the battery is dead..sounds like it's not holding the charge....how old is the battery?
Posted By: stumpy
Re: Weird battery problem - 02/01/09 10:07 PM
1.5 years. Ya I'm confused too.
Posted By: RapidRobert
Re: Weird battery problem - 02/01/09 10:33 PM
either the battery is prematurely (terminally) ill or theres a constant draw in the vehicle. Charge it up, take off one cable, let it sit that way for you said 3 days right, If it's OK obviously there is a full time draw somewhere in the car. Might put a VOM on amperes scale on the lowest scale(micro or milli amps) & in series with the cable you took off & see if there's current flowing. I'd try the amps scale 1st then the milliamp scale 2st then microamps so you dont fry your meter if it's flowing alot of current.
Posted By: stumpy
Re: Weird battery problem - 02/01/09 10:35 PM
As I said earlier I did a draw test and there is none.
Posted By: AARCONV
Re: Weird battery problem - 02/01/09 10:39 PM
what kind of car and brand of battery are we talking about anyways..
Posted By: stumpy
Re: Weird battery problem - 02/01/09 10:46 PM
2005 pt-gt unmarked as to battery brand.. I get a 11ma reading but I don't consider that a draw. It's too little to cause a battery to go dead.
Posted By: stumpy
Re: Weird battery problem - 02/02/09 02:23 AM
The only draw is radio memory. No seperate clock. Battery is unhooked and time will tell.
Posted By: Anonymous
Re: Weird battery problem - 02/02/09 03:30 AM
I would still suspect a draw, although it COULD be the battery, just not likely
I'd unhook the battery
The problem is, that modern rigs have SO much "soft" controlled devices, things are not like back "in the day" --you turned something off, it's pretty much off.
It have an alarm? Maybe something is causing "false" activation of the flash warning, something like that
Another approach, let's say you disconnect, and that shows the "right track"
Maybe next, remove a bunch of accessory fuses and see if that eliminates the problem.
Last what kind of "load test" are you referring to? If the "load tester" is handheld, in one hand, then "it ain't" --a load tester that is
Posted By: stumpy
Re: Weird battery problem - 02/02/09 03:37 AM
No accessories other than the radio to cause a draw. Everything else is off with the key. Like I said I did a through draw test with a VOM and found nothing that would run a battery down in two or three days. The load tester was the cabinet style that senses and charges a battery to full charge before putting a heavy load on it. Then it recharges the battery to full again. I don't trust the hand helds completely but they do work most of the time.
Posted By: Anonymous
Re: Weird battery problem - 02/02/09 03:42 AM
Well my point is that "everything" is NOT off with the key---I'm not familiar with all the new computerized crap, but here's just one example
On a typical stereo, esp with a heavy outboard amplifier, --even on a "stocker" Some circuits are wired so that the main output transistors are across the buss all the time. This doesn't cause any problems until "a problem arises"
Your alternator is the same way. You have diodes that are "hot" all the time. They CAN and do go bad, and I have seen diodes that "leak."
Without painstakingly analyzing the entire circuit of your vehicle, I don't know--but unhooking the battery will tell you if it's in the vehicle or battery.
Posted By: stumpy
Re: Weird battery problem - 02/02/09 03:48 AM
That is what a draw test is for. It eliminates all those things you are talking about. Do you know how a draw test works?
Posted By: minivan
Re: Weird battery problem - 02/02/09 07:00 PM
I had a battery that gave me fits for a couple of years.. Tested out good but things just didn't work right.. Tested each cell and found a bad cell.. Exide battery....
