You would need to provide a diagram of how the batteries are to be connected to be charged. If the 4 batteries are in parallel the output will be 12 Volts and your generator is providing up to 48V indicating you need a high power buck regulator to reduce the (varying with speed) generator voltage to the appropriate (for car batteries about 14.5 V) charging voltage. Charging specs / limits for the batteries would also be useful.
↧