Has BMW given any information on the 12 volt system?

Lead acid or lithium ion?

Looks like lead acid.

I'd be very surprised if it was anything other than lead acid. On 12v batteries, you only see lithium ion used on performance cars where you want weight reduction.

kevinm03 wrote

I'd be very surprised if it was anything other than lead acid. On 12v batteries, you only see lithium ion used on performance cars where you want weight reduction.

And Tesla's, apparently.

sparked wrote

Has BMW given any information on the 12 volt system?

Lead acid or lithium ion?

Any specific reason you'd care either way?

Not OP but I moreso care whether it's AGM or FLA. LFP would be nice honestly, but I know it's still a reasonably more expensive option for 12V.

ggalanis wrote

Any specific reason you'd care either way?

For longer reliability with a lithium ion battery. Also, 12V lead acid has plagued a lot of EV manufacturers. I think the power demands on 12v are generally pretty high on many EVs. Tesla's common 12 volt battery failure went away as soon as they went to lithium ion. I wouldn't say it's a "must have" but a "nice to have" in terms of preference.

sparked wrote

For longer reliability with a lithium ion battery. Also, 12V lead acid has plagued a lot of EV manufacturers. I think the power demands on 12v are generally pretty high on many EVs. Tesla's common 12 volt battery failure went away as soon as they went to lithium ion. I wouldn't say it's a "must have" but a "nice to have" in terms of preference.

I have had a BMW EV for 3.5 years now, and I havnt heard of any 12v battery failures in groups and forums. The 12v battery issue seems to be worse on Korean cars.

A lithium battery isnt going to be more reliable than an AGM battery, AGM's have been around decades, and are extremely reliable.

12v battery failures on EV's is because of bad battery/energy management or an undersized 12v battery. It's not the battery's fault.

You dont want a lithium 12v battery, do you know what they cost to replace?? You have very little choice for after market batteries too.

Any brand will do in case of replacement?

ggalanis wrote

Any specific reason you'd care either way?

Li-Ion batteries have minimal self-discharge. It doesn’t really matter if you drive a car regularly and the manufacturer implemented a proper charging strategy (looking at you, VW).

Li-Ion batteries shine on toys like motorbikes, where they tend to sit for an extended period of time.

I don't see much of a use case for li-ion batteries for the 12V system.
My understanding is that they have additional electronics to manage voltage and charging, potentially making them more prone to failure.
An AGM battery works just fine for its purpose - as long as its voltage is properly maintained.
If someone is really concerned about weight, or the 12V battery being drawn down, then a Li-Ion may be a decent choice, but 95% of us wouldn't see any benefit.