I have trawled the forum so apologies if asked recently - Anyone know who replaces 12v batteries ? Can I do myself or will car need computer plugged in? Been told £600 by main dealer. Halfords and Kwik got here not phev trained
Third-party batteries are not quite as expensive as the original ones - but they must be vented and installed correctly, to prevent harmful fumes entering the passenger compartment. There is no computer reset involved.
As mentioned, you can't just use any old replacement. The battery is technically inside the car, so you need to replace it with a similar type. Not sure where you're based, but mention of Halfords leads me to suspect the UK. Richi (of FAQ fame) has a UK Amazon page with various items for the PHEV including a couple of 12V batteries