[kkasson]

When I bought my car, it had an Interstate battery in it. Is there any way to know what battery it came with from the factory?

From what I can tell, there seem to be some with 70 Ah batteries and others with 90 Ah. M3s seem to have come with 90 Ah, and then they were given 70 Ahs as warranty replacements. What about the non-Ms?

My battery is a couple years old and is working fine, so I'm assuming (/hoping) that it was registered correctly when it was installed. But I'm not sure whether it was a direct replacement, or if it was recoded to different specs. When it comes time to replace it, I'd like to put back whatever was originally in it...is there any way to know? Do the dealers even sell 90 Ah batteries, or only 70 Ah?

What about lead/AGM? Did any of them come with AGM from the factory?

It's an 07 328i, manufactured 12/06. VIN is FZ73984.

[ctuna]

Not many come with AGM
The program that you register with is set up with the
battery capacity and type so that is one way to tell.
Most of them them are lead acid 90ah from what I see
here. Go to the coding section and read up on battery
coding and registration. If you change battery types
and capacity's the car is suppose to be recoded for that
type and ah rating.

[jt335i]

Replaced the battery on mine just recently and it looked like this.
Lasted a pretty long time at 5 years, 7 months, and 27 days.

[robthewrench]

e90's had more battery options from the factory than I've ever seen for a single model of car from any other manufacturer.

2 or 3 different amp hour ratings plus conventional wet vs agm were all options.

I think most common was the 600-700 CCA or 70Amp Hr batteries. I believe this is an H6.

My original H6 battery is now nearly end of life and I'm going to replace it with an H8 90 AH (H8 and H6 have the same width and height, but different lengths). The battery location in the trunk is sized for an H8 already since this was a factory option.

I'm sticking with a wet cell, because my car came with a wet cell and changing to an AGM would require re-coding the car to match the different charge cycle of an AGM style battery. You should also register the battery in the car's computer to get it to re-learn a new charging cycle. Both of these will prevent over/under charging and damaging the new battery.

If your car came with an AGM, you should replace it with an AGM since the car is already coded to this type of battery.

It is possible just to ignore register and recoding, but you have the risk of damaging the battery and a shorter battery life.

[kkasson]

I plan on registering and coding whatever I put into it...my concern was just that it may have already been coded to a different battery than what it came with. It's not even a concern really, more just curiosity.

Based on your replies it doesn't seem to make too much of a difference which type is used, as long as it's registered properly.

[fazman]

Originally Posted by kkasson

When I bought my car, it had an Interstate battery in it. Is there any way to know what battery it came with from the factory?

From what I can tell, there seem to be some with 70 Ah batteries and others with 90 Ah. M3s seem to have come with 90 Ah, and then they were given 70 Ahs as warranty replacements. What about the non-Ms?

My battery is a couple years old and is working fine, so I'm assuming (/hoping) that it was registered correctly when it was installed. But I'm not sure whether it was a direct replacement, or if it was recoded to different specs. When it comes time to replace it, I'd like to put back whatever was originally in it...is there any way to know? Do the dealers even sell 90 Ah batteries, or only 70 Ah?

What about lead/AGM? Did any of them come with AGM from the factory?

It's an 07 328i, manufactured 12/06. VIN is FZ73984.

Don't waste time trying to look up what the car came with if the battery has already been replaced once and has unknown history.

1) Find a coder or get your own $20 OBD2 K+D Can cable and have someone help you setup/remote code you (Far better option)
2) Go to AAP and buy the AGM H8 battery which should be a 90+AH battery. Use the following coupon code "HUGE50" to get $50 off $175.
3) Either get AAP or someone to help you install the battery in your car and then quickly have someone code the battery to the correct charging profile so it doesn't stress out the battery.
4) Code the car for the 90AH AGM, Update the VO for the AGM 90AH battery, and lastly register the new battery
5) Have the local/remote coder setup your car with all the other cool features that you can choose from while coding.

DONE!