Wiktionary
powering up
vb. (present participle of power up English)
Usage examples of "powering up".
There was a hiss and a little whine as steam was pushed through thin pipes, slowly powering up the constructs analytical engine.
Don is already powering up the ship's engines as Smith tries separating himself from the tiny lizard monkey.
The TIE fighter immediately hummed, indicating it was powering up.
There was a humming sound coming from the vehicle, the noise of a weapon powering up.
He flicked them and heard a nearly inaudible whine of the batteries powering up.
His crew chattered around him on the bridge, powering up the ship's weapons and shields.