I run an 85/55 Watt Halogen head light and 2 x's 35 Watt Halogen Blue flood lights off a Toggle-Sx when required. My 72 750 SF has a 32 Amp Bosch generator and I run an Gel Scorpion YTX14-BS 12 Volt AGM Maintenance Free Battery.
I do a lot of night cursing, some 1000 miles where, at some point, I do have to put a 3 Amp over night charge on the Battery as the Generator really does not put out enough out to fully maintain the AGM battery. 5 Years now and the Battery is doing fine.
My alternative is to replace the Bosch Generator with a Japaneses Ansi or Hatichi alternator but I'm content with what I have for now.
I must point out is that if you run the old Bosch regulator with generator, ensure you mount the regulator on Soft Rubber brackets or you will fry contact points due to vibration.
You are taking a chance, if you run the VW 30A regulator, of burning the field coils of your Bosch Generator :0(
One thing about a Breganze, if you have enough energy for the battery to fire the plugs you can always push start her and that Generator Belt is one mean sucker to find, if you find a source, buy 2 or 3 of them
