Beta uses Iskra alternators. Interestingly, they wire it assuming a single battery bank, with the positive pole on the alternator wired back through the starter motor. On my previous boat, as well as previously with the Perkins, I had followed Nigel Calder's advice (perhaps now already outdated?) to create a completely separate circuit for the starter battery, only connected to charging sources via an echo charger. Rather than mess with Beta's wiring, this time around I have gone with a single main bank for both house and cranking loads, with a separate "emergency" battery kept topped up via an echo charger while operating under normal conditions.
I had them install the brush kit to bypass the internal regulator on the Iskra alternator, and now use a Balmar MC-614 for regulation. Prior to that change, it was a bit disconcerting to have charging pegged at 14.2 volts for as long as the engine was running. I know people must have done that regularly without frying their batteries in the old days before we had good monitoring and multi-stage charging. And I get (from the good folks at Attainable Adventure) that even the Balmar and most other "smart" chargers aren't actually monitoring current acceptance via a shunt, mostly just running a timed program to cycle through bulk, absorption and float stages. But still I feel better having at least some control over the process and peace of mind if we need to motor for a long time with already charged batteries (which is often, since our primary modus operandi is weekend cruising the often calm Chesapeake in summer, with a boat that sits plugged in at the slip most of the time).