A DC generator driving a good quality MPPT charge controller--It may work just fine... The unknown is how clean is the DC signal and how does it react to the PWM input of an MPPT charge controller (as battery reaches full charge, the input current becomes PWM--Pulse Width Modulated). It can cause grief for a regulated DC output.
But a good MPPT charge controller can connect directly to a battery bank (with DC fuse for over current protection in case of failure) and work just fine. And MPPT controllers are used with wind/water turbines (AC alternators with a rectifier).
It does work, just cannot guarantee it because of the unknowns.
-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
