BMW Battery Replacement and Registering, Battery Cables IBS and BST
Q car year: 2006
car model: 330i
My battery is the original in the car. (e90) Last winter and now this winter it seems that this battery is on its way out. I am researching the proper way to replace the battery. Is this a “dealer-only” thing? I thought i read somewhere that the car has to be programmed to see the new battery or something. What would happen if i just replaced the battery myself (like every other car i have owned)? Please explain the correct steps to replace the battery on this car. I see that it has the bracket over it and the 2 terminals, but there is an extra module or something over the positive post.
See the link below for general information on late model BMW battery replacement issues.
Click HERE for battery replacement and registering info.
Additionally, to address your specific questions:
The positive cable has a Battery Safety Terminal (BST) this is a power disconnect device. The disconnect is activated via the Multiple Restrain System (MRS) module, in the event of a crash.
The negative cable carries the Intelligent Battery Sensor (IBS). The IBS monitors battery conditions.
Finally, there is the rear power distribution panel, which is mounted on top of the battery.
Disconnect the negative and positive cable clamps and lift the cables, clamps and the rear power distribution panel off the battery and lay the assembly aside. You can now remove the battery hold-down (at rear of battery), disconnect the vent hose and lift the battery out.