BMW Repair: Replacement Batteries for 2000 BMW Z3 2.3, bmw z3, battery models

Question
I've got a dead as a door nail battery in my 2000 BMW Z3 2.3, which needs to be replaced.  What are or where can I find listings of the appropriate replacement battery models?

Answer
Kevin, batteries in general are listed in group numbers. They are two digits. I show three different BMW part numbers. I can't tell which applies because it shows that there are none of them in the country and I know that can't be right. All BMW parts have a two year warranty. Your part numbers are:
61 21 8 381 738
61 21 8 368 733
61 21 6 946 332
The most expensive one's MSRP is around $120. Call you local BMW dealer parts counter and give them the last seven digits of your VIN number and ask for a quote.
-Evan