[MSportTune2]

Hi All, I did a search here but was not successful.

On my current F30, the standard AGM battery is 92AH and I understand from checking my VIN and from realoem that I need to change to 90AH which is puzzling. Since I have added amps etc, I am thinking of upgrading my battery to 105AH version found on the F10.

Anybody have done this upgrade? If yes, can you pls share details? I understand the alternator have no problem handling the higher 105AH AGM battery so I would think it is just a swap to 105AH with some coding.

Thanks.

[shivaswrath]

Would you even need to code?

[MSportTune2]

Originally Posted by shivaswrath

Would you even need to code?

It seem that way from several sources that I checked with.

So far nobody have attempted this?

My battery is coming to 3 years and recently my car had a battery discharge warning which was due to testing my ICE upgrade. I thought since I may need to replace soon, I may as well upgrade as I am thinking of adding a sealed box sub in the trunk.

[Polo08816]

Originally Posted by MSportTune2

Hi All, I did a search here but was not successful.

On my current F30, the standard AGM battery is 92AH and I understand from checking my VIN and from realoem that I need to change to 90AH which is puzzling. Since I have added amps etc, I am thinking of upgrading my battery to 105AH version found on the F10.

Anybody have done this upgrade? If yes, can you pls share details? I understand the alternator have no problem handling the higher 105AH AGM battery so I would think it is just a swap to 105AH with some coding.

Thanks.

Can anyone make sense of why the original 92Ah battery must be replaced by a 90Ah battery according to RealOEM?

http://www.realoem.com/bmw/enUS/show...diagId=61_2815

Attention:
The installed 92Ah AGM battery must be
replaced
by the 90Ah AGM battery!

[Polo08816]

Originally Posted by Polo08816

Can anyone make sense of why the original 92Ah battery must be replaced by a 90Ah battery according to RealOEM?

http://www.realoem.com/bmw/enUS/show...diagId=61_2815

I took a look at my battery and it seems the OEM battery is made by Exide: EXIDE EDGE FLAT-PLATE AGM
PART #: FP-AGML5/49.

[Billfitz]

If you've added a lot of high current drain devices you don't need to upgrade the battery, you need to upgrade the alternator. The battery supplies power when the engine isn't running, the alternator supplies it when the engine is running.

[SHoTTa35]

Originally Posted by Billfitz

If you've added a lot of high current drain devices you don't need to upgrade the battery, you need to upgrade the alternator. The battery supplies power when the engine isn't running, the alternator supplies it when the engine is running.

Not exactly true for BMWs. The battery is used more to save the drag on the engine (alternator engaged) for the Efficient part of EffiencientDynamics. This is why you will get low battery issues if you only do short trips and not much regen.

The alternator kicks in when braking as well as when coasting (foot off the gas). Also kicks in when the battery is low to help charge her back up. Your electrical devices pull power from the battery vs from the engine when running.

[Gabrola]

There is no issue with moving to a higher capacity battery, it has nothing to do with the alternator at all. You will however need to have the car programmed for the new battery.