DIN100 in E46 M43

[solo]

Just curious. Is anyone running their E46 M43 engine with a Din100 battery? My mechanic telling me that it will kill the alternator. A search on the net doesn't seem to give any relevant information, hence my asking here.

Salud

 

[OldmanBM]

I have been running DIN 100 Bosch on my M43 for as long as I can remember. No problems .

 

[jarance]

Having a bigger capacity battery would not serve any purpose other than you can crank more times that the rated battery.

BMW have sized the battery according to the AH or din size of din 66 to din 88 (90) according to your engine capacity.

Having a bigger battery capacty is good but you have to consider the output capacity of your alternator.
In normal case where your battery is fully charged, the charging current is relatively low. However,
in the case when your battery is drained due to numerous attempt of fail start, it will put a big strain
on the alternator when it charged the drained battery. Chances it might damaged one of the diode of the rectifier bridge.

In addition, the cost of a Din66 battery as compare to a din 100 battery is quite a lot.

 

[jarance]

Here is a guide from ACDelco Mainteannce Free Battery.

Battery Specification


Recommended Battery for Various BMW Model

 

[solo]

Thanks for the info Mr OldmanBM and Mr J. Picked up a Varta Din75. All is well now.

Salud