simple past tense and past participle of power up

At full power; at the very utmost limit. / For vessels that depends on engines for propulsion that is independent of assistance from any sails.

Using steam power.

simple past tense and past participle of power down

fitted with a battery or batteries, which provide(s) the power to operate the device.

Powered by a gasoline engine.

powered by the diesel engine

simple past tense and past participle of power off

Of an engine, vehicle, device, etc., deriving its energy from sunlight through the use of solar cells.

Powered by itself without requiring an external power source.