The BMW i3 positive battery cable connects the 12V battery to the vehicle's electrical system, often identified by its red protective cap and plus sign, and is crucial for starting the car; replacement cables are available by specific part numbers.
You must ensure correct fitment with your VIN, as it's distinct from the high-voltage (orange) cables.
Part number: 61129359665, 61 12 9 359 665, 61.12.9.359.665, 9359665