[SigmaPiFSC]

Hi, I'm doing the retrofit for the Gesture control. As a part of it, I'll need to access connector for A258*8B I'll need to disconnect it, then add 2 wires to it. I'll also need to disconnect the sunroof controller to replace it. And I'll be adding the other ends of the wires to a connector there.

Do I need to disconnect any battery for this project? If so, which one? I'm in a 2023 530e, so it's a hybrid. In the trunk, I see one battery on the far right, and another in the middle of the trunk. See pictures. Which one should I disconnect if any?

I'm nervous to touch the terminal. Last year, I was helping my daughter jump start someones car (not using mine) and I clipped the black / red the wrong way... it didn't really go so well! The jumper cable sparked and in 5 seconds burst into flames! So, I'm nervous to touch this the negative terminal on my BMW. I also read, that if I do this wrong, it will ignite the airbags. Am I missing something?

Thx!

[BMW012]

hopefully someone who has actually done it can give you some instructions/recommendations. wishing you luck!

[Qsilver7]

To remove the BDC...ALL battery earth leads MUST be removed. This means the main battery (the one in the middle) and the auxiliary battery (the one on the side). REMOVE their negative battery cables…and make sure they DO NOT touch anything metal. Wrap the terminals in an rag, towel, or even an old sock…to prevent any accidental shorts in case the cables get bumped or move and end up touching something metal.

But since you have a hybrid…you also have a high voltage battery…and hopefully you’re prepared and understand how to work with this special battery because its earth lead must also be disconnected:

Work on live high-voltage components is expressly prohibited. Before each operation on the high-voltage system, the system must be isolated from the power supply by qualified personnel (high-voltage safety connector Off) and secured against unauthorised recommissioning (padlock).

After each deactivation of the high-voltage system, it is essential to observe a waiting period of at least 10 seconds prior to further work.

Before beginning work, it is mandatory to check that the equipment is de-energised and is protected against being energised again.

Work is only permitted to begin if:
Display in the KOMBI High-voltage system deactivated.
When a high-voltage warning is active (indicator light, Check Control, etc.), it is essential to determine and eliminate the cause of this warning via the diagnosis system before continuing with any other work. If it cannot be definitively established that the equipment is de-energised, work is not permitted to begin. Danger to life! A qualified electrician must verify that the system is de-energised 1000 V AC with suitable measuring devices/measuring procedures before work can commence.

[Warp Ten]

Originally Posted by Qsilver7

To remove the BDC...ALL battery earth leads MUST be removed. This means the main battery (the one in the middle) and the auxiliary battery (the one on the side). REMOVE their negative battery cables…and make sure they DO NOT touch anything metal. Wrap the terminals in an rag, towel, or even an old sock…to prevent any accidental shorts in case the cables get bumped or move and end up touching something metal.

But since you have a hybrid…you also have a high voltage battery…and hopefully you’re prepared and understand how to work with this special battery because its earth lead must also be disconnected:

Work on live high-voltage components is expressly prohibited. Before each operation on the high-voltage system, the system must be isolated from the power supply by qualified personnel (high-voltage safety connector Off) and secured against unauthorised recommissioning (padlock).

After each deactivation of the high-voltage system, it is essential to observe a waiting period of at least 10 seconds prior to further work.

Before beginning work, it is mandatory to check that the equipment is de-energised and is protected against being energised again.

Work is only permitted to begin if:
Display in the KOMBI High-voltage system deactivated.
When a high-voltage warning is active (indicator light, Check Control, etc.), it is essential to determine and eliminate the cause of this warning via the diagnosis system before continuing with any other work. If it cannot be definitively established that the equipment is de-energised, work is not permitted to begin. Danger to life! A qualified electrician must verify that the system is de-energised 1000 V AC with suitable measuring devices/measuring procedures before work can commence.

Yikes! Does not look like a DIY project. I used to do much of my home electrical work, both 110v and 220v, added subpanels, and even changed a main panel bus bar with the Main off but power still connected to the other side of it (covered in carboard to prevent contact). But I don't think I would be messing with the high voltage electrical systems in today's electric and hybrid cars. Just my thought. --Bob