I wanted to directly address the issue raised by some about not registering / coding their batteries, and the explanation stated here which several posters seem to have missed or ignored.... Because I had the same thought at first but am second-guessing myself now...

At first I did the math...
If the dealer is charging $200-$300 to "register" the battery, and that makes the battery last 20% longer [say 5 years instead of 4 yrs], it would be more economical to NOT pay to have it registered if you just need replace your battery at 4 yrs instead of 5. (since 20% of new battery cost is less than the Register fee)

HOWEVER at least two posters have called out the additional risk of having your electronics potentially incur damage, and other various problems down the road by choosing NOT to register the battery. Just because you didn't register, and its been fine for 4 years, doesn't mean you are not at risk. I would argue that now after 4 years will be exactly WHEN you MIGHT start to see issues.
Or not; who knows. You take your chances.

Same thing goes for Coding your car for a diff type / capacity battery. Double in fact.

So the best route would seem to be to DO the registration (& coding if needed) but finding an indy shop that can do it cheaper than dealer.

All that said, I guess it due to the mysterious sound of "some electronics may incur damage" that most folks dismiss it out of hand. Would be nice to have something a bit more concrete.