[PhreakShow]

Hey guys.

Imagine an E89 or E90, I think they share the same behaviour. You unlock it, enter the car, put the key fob in (no comfort access) and press the button until the MIL comes on and the car turns on kl15.
All doors are open and are never closed. I know that opening the driver's door turns off kl15.

You want the car to stay that way, because either the battery is fully charged or the car is connected to a charger (in my case) and well above 12.5V.

How can you prevent it from turning off again? I tried fastening the seatbelt and turned the light switch to the first position, but no use, it keeps getting switched off. Sometimes accompanied by a battery symbol in the cluster, but that's not always the case.

[gfriedrichi]

Have you tried to turn on hazard emergency lights ?

[PhreakShow]

I have not. I find the to be pretty irritating while doing stuff on the car. I was of the opinion, turning them on makes the car conserve power to have them run as long as possible?

[RuleNormaliai]

turn on parking lights and plug drivers seat belt in.

[PhreakShow]

Parking lights as in "turn the light switch one to the right"? Or the real parking lights? Seatbelt does not help.

[larshutten]

Get a good power supply (50a minimum for Exx 13.5-14v). close driver door lock, put driver seatbelt in and standing lights 1 click to the right on switch.

Oh and use the jump start points under the hood.

[PhreakShow]

Tried exactly that. Didn't work, still shuts off.

[bmchicago]

the state of charge is too low. normal operation. Your car is reporting a problem with the battery. have you tried recharging or replacing the battery so the state of charge is more than the startabiliy limit?

[al70]

he says he has it hooked up to a charger

[Node]

he says he has it hooked up to a charger

To be frank the only definition for "charger" OP gave is "well above 12.5V". I have no idea why 12.5V was chosen as a reference, but AFAIR for a car's energy management software to detect charger voltage needs to be above 13.2 or 13.5V.

And that is assuming car is later model E90 (not like from 2005 or if it is then having software updated to much newer) and car has IBS as not all E90s have it.

P.S. battery symbol on the dash would suggest that car has IBS but then it's also a tell-tale sign that OPs "charger" is too puny.

P.P.S. at least on E60 depending on car options to keep ignition on you need at least 25A to keep car on (of course by switching lights, heating, ventilation, sound off, but if you are doing work on a car which causes various pumps to turn on, you need at least 50A supply to keep up). If car has richer options, easily add 10-20A to these numbers.