A classic problem with built in regulators of the semiconductor rather than
 relay types is that they aren't adjustable.  My BMW Airhead uses the standard
 Bosch current sensing regulator can that has a relay inside, it is adjustable
 to a degree if you're patient.  I run mine at 14.1VDC and check the battery
 level often.  The 280W alternator is barely sufficent for electric vest,
 100W Headlight and taillight + Kettering ignition.

 Now on to Bosch and its built in nonadjustable.  The touted best way to keep
 things up to snuff is cleanliness.  Clean the terminals at the alternator
 clean the connectors shiny bright, use star washers for the grounds and clean
 those surfaces shiny bright.  Of course clean the battery terminals with one
 of those terminal cleaning brushes that will shine up both the inside of the
 cable connector and the battery terminal itself.  This great info comes from
 harboring a VW typ 914 for many years plus 150K on the current westie.

 Caveats:  A lead calcium ("sealed") Delco Group 41 likes 13.9 V for charging
 whereas a standard lead likes 13.7-13.8.  Charging at a higher voltage will
 cause boiloff of the water and significant outgassing of hydrogen and means   
 one must monitor the water level closely to avoid drying out the battery.

 A conversation some time ago with Bosch rep resulted in a "not available" 
 answer for adjustable regulators for the standard alternator.  Now one could
 dump in a Delco 90A and an external regulator...

 For the westie owner with an odd relay in the box behind the driver seat
 this is a battery isolation, charging relay that IS NOT THE SAME AS the
 usual can it has a built in sensing diode that isolates the battery when
 starting yet permits it to charge under normal running conditions.  Smart
 those churrmans eh?

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