[BimmerGuyHere]

I'm just wondering do you really have to register and code a new battery in the e90s?

I've heard some say you only have to do one of those things!

Also what if you get the same exact battery and specs do you still have to code and/or register the battery?

Thanks in advance

[mainbearing]

Just register it so the computer will know there is a new battery in there. The battery capacity degrades about linearly with age, so your new battery will not be under charged and die sooner.

I would not bother to recode it, even if you got a wet cell battery with 80Ah instead of the typical AGM of 90Ah (Costco Kirkland Interstate is 95Ah).

(I recoded it with INPA to 80Ah when I got an Autozone wet cell. Now with the Kirkland AGM somehow I am having problem recoding it back to 90Ah. So I really would not bother to recode and wished I did not.) I am going to re-register the old battery to give the old Kirkland a bit more charge.

[TunafishE93]

Car will run fine just changing the battery, you will prolong the life of the battery by registering, and if you change type, coding. But its not needed for functions.

[Hakentt]

you have to replace the battery with same type and same rating anyway, so no need to register the battery that is identical.

[BimmerGuyHere]

So just register it!?

And I have bimmercode app, can I register it using that and where do I do that at if so?

Do you register it before you put the battery in or after you put the battery in?

Thanks

[Efthreeoh]

If you use the same spec battery, you just need to register that it was replaced. If you change the spec or type of the battery, you need to code the change to the new battery type/spec. The purpose of either is to notify the battery management system the battery was changed.

[BimmerGuyHere]

Originally Posted by Efthreeoh

If you use the same spec battery, you just need to register that it was replaced. If you change the spec or type of the battery, you need to code the change to the new battery type/spec. The purpose of either is to notify the battery management system the battery was changed.

Sounds confusing! Most people say you just have to register it!

I have bimmercode app and a good top Don OBD Scanner with a battery registration under maintenance mode

[lookalikehuuh]

Let's clear things up a bit, do you have to code/register the battery.. No.

Is it better to code/register the battery? ABSOLUTELY YES. Coding/registering a battery help to improve the longterm life of the vechicle's battery. I had a Bosch AGM battery last 10 years before I replaced it as a "precaution"

Here's the scenarios where you should do either one:

Code & Register: You should code the new battery when you replace the battery with a different chemistry or capacity battery. For example, you replace a flooded battery with an AGM, or you go from an H6 (~70AH) to an H8(~90AH). This tells the alternator that different voltage/amperage requirements as AGMs technically require higher voltages and amperage rates.

Register only: You should register a new battery when you replace the exact same chemistry AND capacity battery as what is coming out of the car. This just tells the car it doesn't need to charge this battery as aggressively since its a new battery that in theory doesn't have as much sulfide build up internally.

The entire effort of coding and registering batteries is so the alternator can use more advanced charging algorithum intended to better manager the car's battery life and potentially improve fuel economy a bit by not forcing the alternator to work overtime when its not needed.

[mainbearing]

As others have said, Register when you put in a same spec (or I would say similar spec) battery.

Unless you use a drastically different battery (like H5 as an extreme example) I would not even bother recoding it.

Here is a repeat of what others already said, from BMW of Macon regarding Registration and Recoding, just to confuse more
https://www.bmwofmacon.com/blog/2026...rogramming.htm

Originally Posted by BimmerGuyHere007

Sounds confusing! Most people say you just have to register it!

I have bimmercode app and a good top Don OBD Scanner with a battery registration under maintenance mode