Alternator replacement question - 2003 X5 3.0

[LI_BIMMER]

Based on the great information from previous posts on X5WORLD, I did the following to see if my 7 month old Interstate MT91 battery was the culprit of no start ups.

1) Had my dead battery load tested and it came back with no dead cells and a "good status" that is holds a charge well.

2) Used my digital multimeter on the recharged battery installed with the engine off and it reported ~12.6 volts.

3) Used my digital multimeter on the recharged battery with engine on and all accessories off and it reported ~11.9 volts. With all accessories on and the engine revving @ 2K, it showed ~11.9 volts.

4) Tried above (#3) on my 3 series and it showed ~14.2 volts at idle or the same at 2K with all accessories on.

Based on previous alternator posts and the above steps, I determined that the alternator is not able to charge the battery fast enough therefore draining it. The X sat overnight in the cold (last night) with the charged battery and starts right up today (no hesitation) so I am sure a long drive would drain it (like my 80 mile trip on Saturday morning).

The remaufactured alternator that I am getting for $158 is a great price but I was asked if it was made by Bosch or another manufacture (Bremi?). Does anyone know if they came across another manufacture other than Bosch when replacing their alternator on 3.0 engine?

Also, is the replacement of the alternator done from the top of the engine bay or bottom? I will be doing the swap on Tuesday. Many thanks!