Battery Discharge

RETSEHC

MEMBER
1999 BMW 323
6 CYL
2WD
AUTOMATIC
129,000 MILES

Both batteries drained out today, first the BMW at 10:00am then my Honda at 8:30pm. Garage kept at my home (concrete slab) built in 2007. I keep the vehicles clean and regularly serviced.

I have no changes to the environment except unbox a metal shelf that are grates. 64in x 35 in that is 15 ft from the BMW trunk. 5 ft from the Honda battery.

I have parked the Honda in the front of the house and moved the BMW to the driveway.

Am I to assume that an electro-magnetic field is draining my batteries? How can I test the theory?

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

No, the current draw from something in the cars is causing the draws.

You need to remove the negative cable from the battery and use a voltmeter in line. Red lead to the cable and black lead to the battery post. Set the meter to DC amps and tell me the reading.

Do that to both cars.

Here is a guide that will help with the most common issues causing this draw so it is worth running through just to make sure one of these is not causing the issue.

https://www.2carpros.com/articles/car-battery-dead-overnight

Let us know what you find. Thanks

Roy