Correct/good alternator voltage for 2009 Jetta TDI???

My palms are small enough but the alternator is really tight fit, covered by two coolant pipes and the intake plumbing from the IC. Anyway, thanks for confirmation, I'm taking a flashlight and a mirror, looking up the existing voltage regulator p/n and ordering a new BOSCH one.

What is the maximum voltage the system can tolerate or is happy with.

Not the battery but the system. If i have a 16v power supply connected to the car without a battery will I damage something? What about 18V.

Also is the charging voltage and algorithms adjustable with something like vagcom?

(Asking for 2012+ vw’s)