Low battery

[gregory20]

Been having issues with my e93 M3 battery being too low to star the car. The battery was change the battery 3 months

This is what is going on

-Drove the car yesterday. When to go drive it and the battery was too low to start the car. Charge it while i was at work.

- Checked the Volts (12.46) and took it for a drive. Got back checked the Battery Volts and it was 12.36.

- had it sitting for 30 min and tried to take it back out and the Battery was too low to start the car 10.12

Also fuse #61 for comfort access and start stop keeps popping.

[TX]

Originally Posted by gregory20

Been having issues with my e93 M3 battery being too low to star the car. The battery was change the battery 3 months

This is what is going on

-Drove the car yesterday. When to go drive it and the battery was too low to start the car. Charge it while i was at work.

- Checked the Volts (12.46) and took it for a drive. Got back checked the Battery Volts and it was 12.36.

- had it sitting for 30 min and tried to take it back out and the Battery was too low to start the car 10.12

Also fuse #61 for comfort access and start stop keeps popping.

Evening.
Two things cause that amount of discharge:

1 - A bad battery.

2 - Some component of the car is not shutting down properly. Usually when this occurs, there is a warning the next time you start the car about excessive discharge while the car was turned off.

For now I will assume your alternator is charging or else you'd have a lot of other warnings on the dash and a lot of things will not work properly. You can easily check this while the car is fired up. You should have ~14V DC at the battery or charging post to ground under the hood.

I'd start with getting someone to check the battery. 3 months old? You should go back where you purchased it and have them replace it if it's bad.

Edit: I missed your last comment about the fuse. That throws most of my answer out the window. You could have a short someplace or something has failed in such a way that it is pulling more load than that fuse can handle. You'll need to take it to a shop with experience on these cars.

[brandnns]

Make sure something isn't still turned on when the car is shut off. I had a fan that was behind the climate control that would stay on pretty much all night, and would drain the battery in my e92.

[gregory20]

Originally Posted by TX

Evening.
Two things cause that amount of discharge:

1 - A bad battery.

2 - Some component of the car is not shutting down properly. Usually when this occurs, there is a warning the next time you start the car about excessive discharge while the car was turned off.

For now I will assume your alternator is charging or else you'd have a lot of other warnings on the dash and a lot of things will not work properly. You can easily check this while the car is fired up. You should have ~14V DC at the battery or charging post to ground under the hood.

I'd start with getting someone to check the battery. 3 months old? You should go back where you purchased it and have them replace it if it's bad.

Edit: I missed your last comment about the fuse. That throws most of my answer out the window. You could have a short someplace or something has failed in such a way that it is pulling more load than that fuse can handle. You'll need to take it to a shop with experience on these cars.

Thanks really appreciate it. I was running my Carly app live read out and it said i was getting 14V~ when the car is running.

Also the car keep jumping into limp mode due to the voltage drop

I'm pretty sure there an over current somewhere that's causing the fuse to pop just down knock where to start looking

[gregory20]

Originally Posted by brandnns

Make sure something isn't still turned on when the car is shut off. I had a fan that was behind the climate control that would stay on pretty much all night, and would drain the battery in my e92.

Thanks i will run a scan to see if anything pops up

[TX]

Originally Posted by gregory20

Thanks i will run a scan to see if anything pops up

Do you have CAS?
https://www.m3post.com/forums/showthread.php?t=1618114
https://www.e90post.com/forums/showthread.php?t=1268679

There was discussion here regarding fuse #61 blowing and whether or not your CAS functions. Also mention of failed door handle. Hope this isn't sending you in a wrong direction.

[gregory20]

Originally Posted by TX

Do you have CAS?
https://www.m3post.com/forums/showthread.php?t=1618114
https://www.e90post.com/forums/showthread.php?t=1268679

There was discussion here regarding fuse #61 blowing and whether or not your CAS functions. Also mention of failed door handle. Hope this isn't sending you in a wrong direction.

Thanks buddy this is awesome. From what i read from there post sound like the Door sensor might be bad. Thanks for all the help. Hopefully this solve the car draining the battery issue also

[Mvy]

Ive also seen ECUs going bad that draw current when the car is off. When that happens If I remember correctly, the start stop button lights up long after the car has been shut off. Maybe check that if all else fails. Wishing you an inexpensive resolution to the issue.

[VtecforV8]

Originally Posted by Mvy

Ive also seen ECUs going bad that draw current when the car is off. When that happens If I remember correctly, the start stop button lights up long after the car has been shut off. Maybe check that if all else fails. Wishing you an inexpensive resolution to the issue.

EDC modules going bad lead to exactly this, I think (Maybe ECU, too--no experience with that one). My EDC module was draining power for a year, then stopped for about six months, and has started doing it again. Time for me to pick one up, I guess, but hopefully not new given the cost.

[Route 16]

My issue was having a lead battery all this time, when I should've gone AGM.
With all the accessories I have, it's no wonder I kept replacing lead batteries even though it's good enough to turn the ignition and drive off.
Also had my shop check my accessories and run it off 30G when it all powers up and down.

[Redd]

I had an issue once where my batt drained to zero because one of the terminals was not as tight as it should have been. No errors when this happened. Reseated and tightened all the terminals and has been ok ever since.