Stator
Also called motorcycle stator, alternator, generator, charging coil
A stator is the fixed ring of copper coils inside a motorcycle engine that, with magnets spinning around it on the crankshaft, generates the electricity that charges the battery and runs the lights.
What does a stator do?
It is the motorcycle's alternator. A ring of copper windings sits still inside a cover on the side of the engine, and a rotor carrying magnets, the flywheel, turns around it with the crankshaft. The moving magnets induce a current in the windings, a regulator/rectifier turns it into steady DC at around 14 volts, and that runs everything electrical on the bike and keeps the battery charged. On many bikes, the Suzuki DR650 among them, the stator sits in the engine oil.
Why riders care about its watts
Because the rating is the whole electrical budget. A dual-sport's stator is typically rated around 200 watts, and the headlight alone takes 55 or 60 of that. The figure in the manual is a maximum at a stated engine speed, often 5,000 rpm, and output falls well below it at the low speeds of trail riding. Anything you add, auxiliary lights and heated gear above all, has to fit inside what is left. Aftermarket high-output stators exist for many bikes for the same reason.
See also
Seen in