Filming & Production
Dummy battery
Also called: AC coupler, mains adapter
A dummy sits in the battery bay with a cable running out to a power supply, sometimes sold as an AC coupler or a DC coupler. Interviews, live streams, timelapses and any locked-off studio setup are where it pays for itself, usually at less than the price of one spare battery.
Buy the version made for your exact camera and check the voltage matches. Cable management is the other consideration, because the lead holds the battery door open and an unsecured one can drag the camera or work itself loose mid-take. Tape it to a tripod leg.