I have for sale my old battery from my E39 M5, which was purchased from BMW last June (I still have the invoice, and the battery is date stamped too).
It's the proper E39 M5 spec battery and was £157 new. I replaced it with a higher spec Bosch battery and have had the battery fully checked at an Auto Electricians, as well as fully charged on a de-regulated charger (removes any sulphation on plates). I have a battery check report and invoice, with state of health and state of charge both showing 100%, and the green light on the battery is showing. As such, it is as good as new.
I want £80 for the battery, a saving of £77 on the BMW stealer price.
Must be collected from Coventry, West Midlands, UK.
PM for any further ino. Cheers