89' Alpina B10 3.5 - Battery Overcharge & consequences

[maxlgd]

Hello guys,

I recently (yesterday) did a pretty solid mistake on my Alpina B10.
After a decent drive, I park my car back in the garage, plug my "intelligent" battery charger to make sure the battery level stays consistent as I don't drive the car often and it's stored remotely.
I come back home and notice I forgot the keys (yes I don't close my car cause it's in a safe spot).

I come back today to get the keys and notice instantly that my battery charger is displaying a higher voltage (around 15.3V) and unplug everything.
The keys were left on the ignition switch, but only at the "ACC" level or "accessories", the step after the direction is blocked, but before the entire electronics wakes up. Step 4 being iginition
I believe this is important as my charger used to work properly and is fairly recent so I don't suspect it to be faulty, rather the car was partially turned on and the charger kept charging it.

I turned the ignition switch to step 3, to see what is going on and well the result is :
- there is some noise in the fuse box with some blowing fuses (idk which ones)
- the oil red light is on
- the CD player keeps make some noise as well.

I didn't try to start the car yet cause I want to have your input first, especially because of this oil red light. When I left, the battery indicated 14.5V.

Can anyone help me investigate what happened, how can I fix it, and if I can start the car safely to bring it to a mechanic.

Thank you so much !

Peace.

[Old525i]

I have a 328i BMW from 2008 that survived a faulty voltage regulator and overcharged the battery in three occasions. In the last overcharge event, the battery case swelled and got extremely hot to the point where it deformed. I installed a new battery, voltage regulator and that took care of the problem. When the battery was overcharged, all kinds of gremlins showed up. Wipers would run by themselves, other devices would operate on their own, non existent OBD2 errors were generated, etc.
If your charger over charged the battery, I would stop using it right away. My suggestion is to turn the lights on to drain the battery charge a bit. Monitor the battery voltage until it drops to around 12.6 or so and then see if most faults recover.