I didn't think you had to do this with an E53.

I have no idea if it was done to my X when I brought it for a battery change to the local dealership.But...I read it here,one this forum in few posts.
Weasel or Killcrap would know better.

... why should a new battery be registered?

For the charging system to know that it's new battery,so it adjusts the charging "algorithm".
But again,I read this here,but can't proof it's right myself.
When my battery was replaced,I haven't asked if it was or wasn't registered.

On one of the other threads about voltage regulator failure, one of the guys posted about how to unlock your computer so you can go through the dash and see what's happening with your voltage etc. It definitely shed some light on why my vehicle is kicking into trans. safe mode. My voltage regulator is throwing voltage all over the map from 16.5 down to 13.2 at times. That explains a lot and probably why it destroyed my battery too.

eh? When I replaced my stock battery with the Bosch I didn't have to register anything and it has been working fine for years until now. I still haven't fingered the problem so we will see.

Braille battery installed. Also took this opportunity to re-install the plastic battery shroud. Had to dremel off the vertical divider piece to make it clear my battery brain stuff.

https://lh5.googleusercontent.com/-V...309_000007.jpg

So seems the voltage fluctuation problem is not nearly as bad now since installing the new Braille battery. Still it seems that when I am idling (@ ~600RPM) I still sometimes float down around 12V. If I gas it up to about 700-750 RPM I always stay above 13V.

Also noticed that my lights slightly flicker at times when idling. I don't think this is happening at higher RPM's.

Barrery and charging system tests AAA can do it on site
 

You can join AAA if you get the Premier at $136. you are entilted to 1 battery each year and its worked out well for me due to a NON AAA shop who didnt have the battery so a napa was changed in less than the 18 months, so this time AAA did their battery test and charger test as well, that said the battery was indeed bad cell and recommended so they changed in my parking lot, and I hope it has not any other item due to being on my 3 water cooled alt, at over $1100 each time, but I will stick with AAA they treat everyone with respect, and will go above and beyond, they do the job right, btw the other shop had me sign a slip to the fact its a hard job to get to the batt in my 01 x5 they want $100.00 more to change the battery because they had to do some work wa wa wa, AAA the correct way to do business correctly !!!

My battery has been discharging after the car sat over the weekend so I unlocked the tests and checked. It said it was at 12.8 idyling and the battery light came on. My Fluke says its at 13.9.

I turned it off & back on (cranks fine) battery light still on and says its at 12.4, Fluke 13.7-9.

I am charging the battery which is at 12.9 on the Fluke with the car off.

How do I reset the battery light?