Battery Issue

[DooLallie]

Hi All,

Looking for some advice / help. We have had our 30i for around 18 months (bought new) over the last 6 months we have been getting a "Low Battery" warning appearing on the infotainment screen, approximately one in every 3 drives, more so over the last 3 months.

We took the car into BMW about 5 months ago and they told us basically to "drive the car more" and fully charged the battery.

Last week we did a 40 mile round trip, car was sitting for roughly 2 - 3 hours. Unlocked the car, a few seconds later get "Low Battery" warning once again. Got outside with a multimeter, voltage was sitting at 11.2.. so popped her on the charger for about 3-4 hours, removed the charger, left her half hour to let any surface charge dissipate and checked again with the multimeter.. voltage 12.6... much better.

This morning, got in the car, no problems at all. Drove roughly 10 miles, parked up for about 5 minuets got back in the car and again, "Low Battery"

Got the trusty multimeter out, voltage is sitting at 11.7.. after only 6 days of her sitting idle. :headbang:

I was starting to think, maybe the alternator.. so started her up, popped the multi meter back in the battery and shoots up to 14 - 15 volts. So that seems okay also.

I've done all the usual checks, no lights being left on or anything like that.

I'm abit stuck as to what to do so any advice is much appreciated


Few things to note:
The battery had to be replaced before we picked it up due to not holding its charge.
Car goes in for its service next week so will get them to have another look.
We do have a ghost fitted to the car.

 

[sumotan]

I change a new battery & had the same issue turns out that the battery was faulty so never assume new battery will be good.

 

[Argyll Andy]

Does your battery charger have a repair/reconditioning function? If so could be worth a try

11.2v is pretty low. I had one reading just under that (10.9v iirc) and my mechanic said it’d never recover properly after being that low.

 

[Sharky11]

Hi,
Just happened to me last week with a 30i that was the same age. It’s a known fault and I now have a new battery supplied by the dealer under warranty. BMW uk were tricky they made the garage carry out some tests twice before they agreed to cover the cost of the new battery. Take no nonsense get a new battery under warranty there seems to be a batch of them with faults.

 

[clarker63]

I'm abit stuck as to what to do so any advice is much appreciated

dashcam without a battery level monitor? That caused the same "low battery warning" on my previous Z4. Even with the power monitor I had to unplug it if I was leaving it on my drive.

 

[PaperSniper]

Does your battery charger have a repair/reconditioning function? If so could be worth a try

11.2v is pretty low. I had one reading just under that (10.9v iirc) and my mechanic said it’d never recover properly after being that low.

Agree. Likely the battery is toast. Also, starting the engine with a low battery can cause problems with the starter motor, so best to get the problem resolved ASAP. I'd waste no time going back to the dealer if the battery is still under warranty. Otherwise, replace the battery somehow.

Doug

 

[dr_john]

A few weeks ago I had a low battery warning on the control display that came on every time I started up. I thought my car battery was on the way out until I realised it was telling me the battery in the remote fob was at fault.

Easy fix!

 

[DooLallie]

Cheers all, will get the local dealer to look into it again, hopefully just a replacement battery will sort it.

We do have a repair mode on the battery charger, and did give it a whirl couple weekends ago.. forgot to mention it in my original post :roll: