Low battery

F

flybobbie

Elite
 Stourbridge
So start car, car on ramp comes up. At first ignore.
Then i go to iDrive menu look up fault...Low battery.
Wonder why. Car is used 5 days out of 7, so why low?

Get obd reader out and look up battery capacity history.
Since i last reset it showing 500+ hours at only 40 t0 60% capacity.
Now 48%.
Perhaps below 50 triggers low battery.

So i'm sat there wondering what's going on, then look at the glove box open and light on...
I'm thinking...is that light going out when i close the door of glove box.
Like the fridge, is the light going out on door close?
Thought i will put my phone inside on video mode...
First time in 2 years phone battery flat! Typical..

So just removed the bulb fitting for now.
I had adapted it to take led bulb, might be a good job.

The plunger that switches the light off rests on the door when closed.
There is a impression mark on the black velvet lining.
But it looks like it just missing a slightly raised section, so might not be switching off.
See next few days if battery % charge increases.
 
Get a simple voltmeter, check battery voltage after you switch off the engine, and then again before you use it. If the drop is significant, could be a battery on its last legs or a parasitic drain. You can also test the voltage when car is running to test if alternator is charging.
 
Have a volt meter fitted always been good 14.3 to 14.7 volts.
If you watch, it shows battery voltage for a few seconds then the electronics kick in to charge it.
Shows 11.7 before start, but of course the battery is not fully charged....
 
When the oil seal went on filter housing it soaked all the alternator area in oil.
I once thought that might be a problem. Tried to clean as best i could with contact cleaner.
I think if i left the car undriven say for a week battery would be flat.
 
Last edited:
flybobbie said:
So start car, car on ramp comes up. At first ignore.
Then i go to iDrive menu look up fault...Low battery.
Wonder why. Car is used 5 days out of 7, so why low?

Get obd reader out and look up battery capacity history.
Since i last reset it showing 500+ hours at only 40 t0 60% capacity.
Now 48%.
Perhaps below 50 triggers low battery.

So i'm sat there wondering what's going on, then look at the glove box open and light on...
I'm thinking...is that light going out when i close the door of glove box.
Like the fridge, is the light going out on door close?
Thought i will put my phone inside on video mode...
First time in 2 years phone battery flat! Typical..

So just removed the bulb fitting for now.
I had adapted it to take led bulb, might be a good job.

The plunger that switches the light off rests on the door when closed.
There is a impression mark on the black velvet lining.
But it looks like it just missing a slightly raised section, so might not be switching off.
See next few days if battery % charge increases.
Click to expand...
Several points..

If the battery has been systematically discharged over time maybe the battery is now goosed..

BMW low battery trigger is when it’s concerned it will not be able to do a cold start at -32c reliably

As capacity diminishes it gets more aggressive in managing the remaining capacity..
 
You must log in or register to reply here.
Back
Top Bottom