You'd only get 40W out of a charging system if you used a cheap half wave rectifier.
A full wave rectifier will give you 95% of input power, depending on efficiency.

They may be called quadracers, but that doesn't mean the only time you should ride one is when you're on a racetrack.
Strictly speaking, they weren't designed for duning either if you go only by their name.
I'm mean, if they were meant for sand, they'd have paddles and a better suspension, right?
An LT isn't really designed for flattrack either, but a few changes here and there and it works fine.
An LT isn't really designed for technical trail riding, but sometimes you can't avoid it...a simple cooling fan over the radiator and it would work fine until you got somewhere to open it back up.
Ride the dunes back to camp with a direct tailwind blowing just as fast as you can safely navigate the dunes.
See how fast an LT overheats when you're giving it plenty of power and no airflow, in a situation it was "designed" for.
Battery powered cooling fan?  No more problems.


Just because a guy wants a cooling fan on his LT doesn't mean he intends to make it a luxury car...