Ancient recharge plate
From The Stargate Omnipedia
Device installed aboard Destiny, designed to recharge remotely powered devices that otherwise might not be replenished out in the far universe. Sergeant Hunter Riley and other scientists discovered the device and managed to rig it to work with human technology.
The unit must be closely monitored while recharging Earth batteries since the inferior power threshold can easily destroy human electronics.
KEY EPISODES
Darkness - Riley manages to recharge a handful of Earth-based devices before he receives word from Col. Young that Dr. Rush has ordered a halt on all power-consuming activities.