is that a regulator regulates the current going to the field winding of the alternator. If you increase the current to the field winding the charge rate increases. If you reduce the current, the charge rate decreases. That’s how they all work. The new smart three stage regulators just have logic that tells itself how much current and for how long to push for a given situation. The old mechanical regulators just used a balance beam/spring to do the same thing. The old, first generation smart regulators were the “AutoMac” regulators. They used a series of resistors to adjust the field winding current. Later, they installed a high voltage trip device and a rheostat to adjust the current. It all comes down to the same thing. Current to the field winding. Even if the windless battery wires were hooked up directly to the alternator the regulator is going to regulate everything anyway. There are two output alternators on the market where you can charge off of two different posts on the back of the alternator but I know nothing about them. You might need a separate regulator for each output post but that is only speculation on my part. You might look at the back of the alternator and see if it has two separate posts with two separate cables connected to it. That would be two red positive cables and one black negative. That’s the only way I can think of where you could have two different charge voltages off the same alternators.