Unfortunately there is not a kit that that'll convert your manual opening MaxxFan roof vent to a powered roof vent.
To get a powered roof vent you'd have to replace the entire unit with a powered unit like the MaxxFan Plus Roof Vent w/ 12V Fan, Thermostat, and Remote # MA00-04500K.
This is a powered unit that has a 12V reversible fan that also includes a handheld remote so you can set the thermostat, and change the speed/direction of the fan. view full answer...