Hi,
I'm in search for an alternator, as a spare unit incase my existing decides to go south.
Rimmers of UK offers one at 138 GBP and said to be manufactured by Rotating Machines, UK.

Would like to know your views on this part.

Thanks

Diesel alternator is the same Valeo one used on M51 diesel used in older BMW. Some parts for alternator fits from VW, for example voltage regulator, slip rings etc

Rimmer's one fitted & running. Seems okay but max charging voltage is 13.8 V. Same as the one I had.

I think 13.8 is in the correct range for an alternator.

13.8V was correct for the standard lead acid batteries that were current when the P38 came out. Newer Calcium batteries can cope with a higher charge voltage so more modern cars are fitted with an alternator with a set point of 14.2 or even 14.4V. Fit an old school cheap battery with a high output alternator and you will cook it but 13.8V will still charge a Calcium battery without a problem.

Update.
Battery +ve terminal cleaned and the charging jumped to 14.2-14.3v.
For me its very good as my old alternator dropped to 12-12.5v when AC ON. Now it drops only to 14.1V.