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Like the titles says. Something is draining my battery when the car sits for a week or so. Drains it so completely that it can’t be charged. Went through three batteries. Any ideas? I think this is causing other problems.
As I’ve mentioned in the past sometimes I’ll shut off the car and when I go to restart it nothing. Totally dead. I found if I do a hard reset it starts right up.🤔
Zero dollar fix to try - clean the key hole behind the steering wheel. There’s a flap there which sometimes gets gummed open and keeps the car systems on.
If you lock yourself in the car, lights go out, can you see or hear anything still running. Ryan B had his music system Amp on all the time.
So tracking down a battery drain is a PITA.
First thing is to put a multi meter in series with the battery to measure the current. Open all the doors, trunk and bonnet. Wait and let the car go to sleep. Takes about an hour.
Car should have only 150mA draw. If higher than that, something is still alive. Now you’re in the realm of pulling fuses and checking the multi meter reading to see which system is still on/faulty.
Good luck.
BTW Completely flat AGM batteries may be repaired by pulsing. Most modern battery chargers/tenders have this function. Worth a try.
Zero dollar fix to try - clean the key hole behind the steering wheel. There’s a flap there which sometimes gets gummed open and keeps the car systems on.
If you lock yourself in the car, lights go out, can you see or hear anything still running. Ryan B had his music system Amp on all the time.
So tracking down a battery drain is a PITA.
First thing is to put a multi meter in series with the battery to measure the current. Open all the doors, trunk and bonnet. Wait and let the car go to sleep. Takes about an hour.
Car should have only 150mA draw. If higher than that, something is still alive. Now you’re in the realm of pulling fuses and checking the multi meter reading to see which system is still on/faulty.
Good luck.
BTW Completely flat AGM batteries may be repaired by pulsing. Most modern battery chargers/tenders have this function. Worth a try.
David could not have put it better myself. Right up to and including the battery charger. Buying a new charger is better and cheaper than buying a new battery.
Regarding the checking of fuses etc there are a couple of good Youtube videos out there who explain how to find a battery drain. Worth a search.
First check the "gate" in the ignition key slot. Does it stick in retracted position? If yes car will not go to sleep.
Do you have a volt meter? Are you comfortable using it? If so we can help you track down other drains.
John
The key switch was the first thing I checked. Seems to be fine. As far as the volt meter. Not sure how to find a battery drain with it. My son probably knows.
Zero dollar fix to try - clean the key hole behind the steering wheel. There’s a flap there which sometimes gets gummed open and keeps the car systems on.
If you lock yourself in the car, lights go out, can you see or hear anything still running. Ryan B had his music system Amp on all the time.
So tracking down a battery drain is a PITA.
First thing is to put a multi meter in series with the battery to measure the current. Open all the doors, trunk and bonnet. Wait and let the car go to sleep. Takes about an hour.
Car should have only 150mA draw. If higher than that, something is still alive. Now you’re in the realm of pulling fuses and checking the multi meter reading to see which system is still on/faulty.
Good luck.
BTW Completely flat AGM batteries may be repaired by pulsing. Most modern battery chargers/tenders have this function. Worth a try.
as soon as I get a new battery I’ll try sitting in the car after shutting it down.
The XK8 I bought to do an LS conversion on had this issue also. It's not registered so it's been sitting for about a month. I went out to start it and the battery was stone dead. The PO had put in a new battery in April 2019. I put a 2 amp charger on it and let it sit a few days and could only get a few clicks out of it. I read this thread and checked the shutter in the ignition key slot and sure enough it was stuck open. A few drops of Kroil and it snapped shut.
I've had the battery on the charger now for a few days. I'll let it sit a few more days and see if the combination of being dead and cold temperatures have permanently damaged the battery. At 2 amps I assume it will take awhile to bring it up to full capacity.
Thanks for the solution guys. This forum is a real asset.
I just went thru this... Seems to be solved but I won't know if I'm out of the woods, not for a while... Car was under water a couple of years ago,,, so I'm expecting months of CRAZY, lol
I've gotten it down to .53 mA... At first,,, as soon as things are shut off and down,,, it hovers at about .80 mA - DMM SET AT 20m - then, in about 5min or so, down to .50mA. DMM set at 2 or 20mA
I'm assuming you watched the Video with the multi meter... It works like a charm...
Turn car off but leave radio on and heater on low. Might sound funny but I turn my car off with these things running Alllll the time. In my mind,,, leaving things how they could be makes sense.
Change the ports on your DMM. I set mine to 20mA
Close everything as usual except the boot so you can get to the battery. For now, unplug boot lights. This was my process... Remove negative battery cable once lights die and car settles a bit. Place positive DMM lead (clip it) to negative terminal,,, clip negative DMM lead to negative earth strap cable. Wait... At this point car is drawing LOW enough power that everything that is powering care systems IS flowing thru your meter. SO BE CAREFUL. Definitely don't start the car or your meter will pop like popcorn. Careful with doors, bulbs even. DONT turn on heater fans like this, for instance.
I would guess you'll see anything from like .80 up to 3, 4 or 5 amps to start and it will quickly fall... Unless something is really drawing...
If you do find something significant,,, pls, write back! And we can keep going.
Last edited by JayJagJay; Jan 7, 2020 at 10:24 AM.
Something is draining my battery.
