[Conezz]

Hi all.

My 2020 330i has a dead battery. I was away for three months. Don't have an outlet for trickle charger.

Got back and the car jump started fine but the battery won't hold a charge very long after the car if off even after driving it for a good 70 miles.

Strange thing is there's no battery warning on the dash.

Still, looks like the battery is shot.

Has anyone info on how to change this without going to dealer and what battery is an exact replacement?

Thank you.

[1WickedE90]

Any reason why you don't just bring to the dealer to have it looked at & possibly replaced under warranty? It should be covered under the 4yr/50k miles new vehicle warranty.

[Conezz]

I’m going to try that. Only thing is it’s 2 years old and 650 miles only.

[NoTanks52]

For those out of warranty, is DIY battery replacement possible, or is dealer support / OEM battery required?

[G22b58]

BimmerLink app together with a compatible OBD-adapter can display the car's estimation of the battery charge.
(Note that charging is slow, also for a healthy battery. A normal standby consumption is not far from 1 Ah per day.)

I haven't tried but "BimmerLink" also has functionality to inform the car electronics of a battery replacement (to the same type/capacity).
"BimmerCode" should be able to change the coding to a new capacity, if needed.

[danallxt]

Got back and the car jump started fine but the battery won't hold a charge very long after the car if off even after driving it for a good 70 miles.

70 miles will not charge a dead battery even if jump started.
You never indicated it you got the battery properly up to a full charge after the period of sitting. You need to have it placed on a charger and then check for full charge with voltmeter after the battery as set for a bit after the charge. A small trickle charger will not bring back a badly discharged battery, a 10 amp charger is necessary to bring it back once discharged to that level. It is likely the battey is still good but just has not been properly brought up to full charge.