Cart motor power consumption basics?

[YotaTruck91]

I am looking to utilize a golf cart motor as motive power for a boat. I haven't decided on inboard or outboard yet-at this point I'm just trying to get an idea of how much battery capacity I would need. The reason I'm looking to go with a golf cart motor is so that I can take a larger boat (20' LOA x 5' beam) with the whole family (four people) out on electric only lakes. From what I've seen online an 8-10 HP cart motor can be had for about $500 and they seem to weigh around 50lbs? The question is, how much capacity would I need to run at various levels of throttle (1/4, 1/2, Full) for how many hours? The max amp draws are always listed in the specs, but, of course, the motor is not always going to be pulling that much.

For example, one online retailer lists an 8.6 peak HP motor as "36 Volts/275 Amps." Lets assume I wanted to run full throttle for one hour-how much battery capacity would I need? Once I have that number, would it be correct to assume that I could go twice a long at 1/2 throttle and four times as long at 1/4 throttle?

Finally, would it be feasible to carry a small camping generator onboard to recharge the batteries? A lot of guys in the bowfishing community do this, but they are usually working with 70-80lb trolling motors. Also, they use RV converters which convert 120VAC to 12VDC-would there be a way to charge my batteries all at once even though they're wired in series for 36VDC?

[Gregorio]

You might want to call these guys. http://www.thunderstruck-ev.com/ They probably have already done what you are trying to do.

Greg