Rapid regeneration protocol
A rapid regeneration protocol could be used to recharge a depleted protostar drive using power from its proto-core.
In 2384, Drednok reported that the USS Protostar's proto-drive's power was depleted, and he could enable rapid regeneration protocols to recharge it on the Diviner's orders. However, Drednok discovered that the crew had removed the ship's proto-core. (PRO: "A Moral Star, Part 1")
After retaking the proto-core, the Diviner was able to recharge the proto-drive, although it took 10 minutes to do. (PRO: "A Moral Star, Part 2")