Hmmm looking at the site, there is a whole break down of the different types, but NOT ONE has anything about battery reset. Which version did you get? The enthusiast?

 

So if I understand correctly, if you were to change from a 90AH to a 110AH battery and used a jumper when changing so the system still had power, you would still need to register the new battery regardless of there being no power interruption?

 

That's what I understand as well. I guess if you don't, the control unit would still think you have a lower capacity battery.

BTW, I remember reading a thread(s) that people that installed new batteries and did not register, had their batteries fail prematurely. I may be wrong, but I guess it's probably because the system was still charging it as a lower\dying battery so it ruined the new battery.

 

I looked in my owner's manual, and it doesn't say what the Cold Cranking Amperage (CCA) rating is of the OEM battery for my 2006 530i. Does anybody know that information? When you live somewhere cold, it's the most important spec, and OEM batteries are crap. CCA is different than the Reserve Capacity numbers that people tend to throw around.

A decent after market battery should provide 800-900 Cold Cranking Amps. I suspect the OEM BMW battery is far below that.


FROM THE WEBSITE OF MY LOCAL AUTO PARTS SUPPLIER

Cold Cranking Amps (CCA) rates the amount of cranking power a battery can deliver to start your engine. The higher the CCA rating, the more power your battery can provide on cold winter days.
CCA = the amount of current that a battery can deliver for 30 seconds at -18°C (0°F). Measured in amperes.

Reserve Capacity (RC) represents the length of time a battery can supply the electrical power needed to run a vehicle in the event the alternator fails.
RC = the time that a fully-charged battery will continue to deliver 25 amperes of current at 26.7°C (80°F). Measured in minutes.


Why Cold Cranking Amps Matter
As the temperature gets colder, a battery?s available power decreases while the power required to crank an engine increases. If you live in a cold climate, look for a battery with the highest possible CCA rating.

Temperature........Available Power from Battery.......Power Required to Crank Engine
Summer
26.7°C (80°F).........................100%............... ..............................100%
Zero
0°C (32°F)................................65%......... ...................................155%
Freezing
-17.8°C (0°F)............................40%.............. ...............................210%
Extreme Cold
-35.6°C (-32°F).........................25%................. ............................350%