E46 (1999 - 2006)
Per FAST Bob, I checked the battery it has 12.5-12.8 volts per digital volt meter.
By-the-way, it's a new, within the last few months, Odyssey PC1200MJT.
I put the battery on a CTEK 3800 charger/maintainer for 12 hours and got the green light, fully charged indicator, almost immediately.
The...