[2JPW]

I replaced my F32 battery with a new Bosch 019AGM and registered it. When charged it reads 12.56V.
After a day of not driving the car it drops to 12.03V

Doesn't seem right, anyone had similar, or is this normal with all the electronics?

With the engine running it's charging at 14.8V

[bishbosh]

Well it is a 12V battery isn't it?

[2JPW]

Originally Posted by bishbosh

Well it is a 12V battery isn't it?

Yes, although I thought that a good, charged AGM battery should read 12.5V or more

https://www.bmwatlanticcity.com/how-...antic-city-nj/

[bishbosh]

The battery in mine is a Varta AGM which I've had for about 3 years, just checked it now and it reads 12.28V at rest.

How long have you had the battery?

[2JPW]

Originally Posted by bishbosh

The battery in mine is a Varta AGM which I've had for about 3 years, just checked it now and it reads 12.28V at rest.

How long have you had the battery?

New battery fitted between Christmas and New Year.

Had you recently driven yours?

After driving mine sits at 12.5V but after a day without use it had dropped to 12.03V

Multimeter records same values as OBD 2 reader.
The 12.03V would recover if I wait the 10mins for all the things the car turns on by default to turn off!

[HighlandPete]

Originally Posted by 2JPW

I replaced my F32 battery with a new Bosch 019AGM and registered it. When charged it reads 12.56V.
After a day of not driving the car it drops to 12.03V

Doesn't seem right, anyone had similar, or is this normal with all the electronics?

With the engine running it's charging at 14.8V

That does appear to be a fast discharge. Even without use, I'd expect a couple of weeks at least, (with maximum closed circuit losses) before it drops that much.

Any warnings? BTW, why did you replace?

[MY340i]

normal

[2JPW]

Originally Posted by HighlandPete

That does appear to be a fast discharge. Even without use, I'd expect a couple of weeks at least, (with maximum closed circuit losses) before it drops that much.

Any warnings? BTW, why did you replace?

Replaced as I kept getting battery warnings. Left it on CTek whilst away for a week and still got low voltage warning. Figured 7 1/2 yrs on AGM was reasonable as I do fairly short journeys.

[HighlandPete]

Originally Posted by MY340i

normal

Not normal, if you are checking like for like, say a locked car in sleep mode.

The voltage change is like seeing the battery drop something like 75% SoC in 24 hours.

[HighlandPete]

Originally Posted by 2JPW

Replaced as I kept getting battery warnings. Left it on CTek whilst away for a week and still got low voltage warning. Figured 7 1/2 yrs on AGM was reasonable as I do fairly short journeys.

Was that something like a "battery discharge while stationary" warning?

I suggest you most likely have a parasitic drain. Anything not been working correctly? Fitted with Comfort Access? Is the car going to sleep?

[2JPW]

Originally Posted by HighlandPete

Was that something like a "battery discharge while stationary" warning?

I suggest you most likely have a parasitic drain. Anything not been working correctly? Fitted with Comfort Access? Is the car going to sleep?

It was that message if I remember correctly. The dash cam is plugged in to the auxiliary socket, so that stays live for 10mins every time the car is unlocked/locked. It does have its own battery too. Also iPod plugged into armrest.

I'll disconnect those two the next time I park and see what the difference is.