Don't bother registering it unless you can get it done for free. It's not worth the cost and will likely not make any difference anyway. I didn't do mine and haven't had any problems after three years. A lot of other members never did it either. I'd bet that registration is primarily a marketing tool/ploy to get you to use the dealer to replace the battery and that is simply insanely expensive. And remember, that Autozone battery you buy has a pretty decent warranty, so if for some reason it fails a little early, just get another. Do the math.

 

I bought a 2007 550i recently. It had the battery replaced by the seller with an AGM battery. The battery registration (intelligent battery system reset, also how you alter the capacity and type of battery if the new battery is different from the old) was not done by the seller, a domestic brand new car dealer.
I have access to a tool that does registration so I did it after I had the car a couple of weeks. I have a radar detector with selectable display set to show voltage when no alerts are present. I saw voltage prior to registration while driving and idling of 14.9 to 15.4 with it staying 15.1 to 15.2 while cruising after a while.
After registration the voltage is 14.6 initially and settles to 14.1-14.3 cruising. I didn't touch the battery or do anything but registration and then drive the same commute every day.

This tells me that the myths of registration are really facts.
The system may not do much as to "smart charging" for lead acid batteries if that is the setting and type of battery. With AGM type the rate of charge affects lifespan more. AGM should not be overcharged and with age the charge voltage can and should go up to optimize life.
My point being that this is a subject with a lot of variables and doing it wrong usually has no short term symptoms or for lead acid batteries maybe never has any ill effects.

 

I have ready that BMW must be "registered" whenever battery is replaced. Also have read no need to register if the replacement battery is identical to the previous battery. I have a 535i 2008 with AGM BMW battery showing end of life issues after after 7 years of use.

Any consensus on this?
Thanks.

 

Here is what is happening: When your battery gets older, the cars computer is telling the alternator to charge the battery more. So if you so not register the new battery, the car will continue to overcharge the new battery and the only thing it will affect is probably the battery life. If you can get the battery registered under $40, get it done. If not and you have an autozone battery with 5 years of warranty or such, do not register it and just replace it when it gets back. At the worst, they will prorate it and you will have to spend $20.

 

Thank you!