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Battery draining, but everything checks ok. Ideas?

Posted: February 15th, 2011, 6:32 pm
by Dark_Rider2k3
Okay so I had this tested at 3 different places. Advance Auto, my friend/mechanic's battery/load tester, and another local auto parts store.

All of them read the battery was good. They also read a good alternator (which is obvious as mine is new).

Now you'd think it's a battery drain right? Well no... they read with the car off 0.018 amps of drain.

Now not only this, but the battery will drain FAST at times. Like.. most of the time I will stop driving, car off, go inside for a few minutes, back out, and it's down to 11.5 volts.

And yesterday I had just tightened up a heater hose I didn't have on all the way so to make sure it wouldn't leak I let it run for a while and then I got some crap out of my mom's house and said goodbye.. ran idling for around 45 minutes... so I go to leave but realize that I left the bricks behind the car.. so I turn the car off and take them off the tires (leaving the key in and interior lights on) but when I go back to the car it's down to 10 volts.. in a matter of seconds!!!

So what's causing my battery to drain? Is the battery itself dead? I'm just confused!! I'm only showing 0.018 amps of draw with the key off so that is within spec if I'm correct...

Re: Battery draining, but everything checks ok. Ideas?

Posted: February 15th, 2011, 7:20 pm
by RS_OBD'oh_2
how did they test the current drain? They would have to open the cct and place the meter in the direct path... Which side did they open? Do you have any extra wiring (amp, cap, etc)?

Re: Battery draining, but everything checks ok. Ideas?

Posted: February 15th, 2011, 8:19 pm
by Dark_Rider2k3
RS_OBD'oh_2 wrote:how did they test the current drain? They would have to open the cct and place the meter in the direct path... Which side did they open? Do you have any extra wiring (amp, cap, etc)?
they tested the drain pretty much the same way I did. Remove negative battery and hook a multi-meter in-line. Advance did it with some battery/load tester they had that read it out so idk how that one works haha.

Re: Battery draining, but everything checks ok. Ideas?

Posted: February 19th, 2011, 1:04 am
by mxmikey
disconnect your battery when the car is off if it stops having problems that means it was a power drain, if it still does not work then it is either your battery or alternator. It will suck to do but it will give you the answer.

Re: Battery draining, but everything checks ok. Ideas?

Posted: February 19th, 2011, 1:34 am
by crazycanadian
Dark_Rider2k3 wrote:
RS_OBD'oh_2 wrote:how did they test the current drain? They would have to open the cct and place the meter in the direct path... Which side did they open? Do you have any extra wiring (amp, cap, etc)?
they tested the drain pretty much the same way I did. Remove negative battery and hook a multi-meter in-line. Advance did it with some battery/load tester they had that read it out so idk how that one works haha.

Current probe is how advance auto did it... I do the same thing this way you don't have to remove any battery terminals.. when you are looking at things does your car have a hard time starting or what ever when the volt gauge drops that low?? are you using an aftermarket gauge or stock one??

Re: Battery draining, but everything checks ok. Ideas?

Posted: February 19th, 2011, 9:15 am
by Ryan
I STILL vote it just needs a good 2 hour drive.

Re: Battery draining, but everything checks ok. Ideas?

Posted: February 19th, 2011, 12:39 pm
by Daninski
If your starter is shorting instead of drawing 150 or so amps on start it could be drawing like 400amps and that's enough to kill your battery every time you start the car and driving around for 1/2 -1 hour isn't enough for the battery to recover. You'd need to have a current draw test done on the starter or swap it out if you have a spare.