The Spycameras and transmitters usually run off of 12 VDC. We provide the power in one of three ways depending on the surveillance system: 1. A 12 VDC transformer is built into surveillance units that normally require power via an electrical plug (Clock Radio, Air Purifier, Boom Box, etc.). The transformer taps off of the incoming 110 VAC from the electrical outlet. Therefore, when the surveillance unit is plugged in and operating, the transmitter and camera are operating as well. 2. A "UV12VDC" 12 VDC transformer is provided for use with surveillance units that do not normally run off of power from an electrical outlet and are too small to house a built-in battery (Smoke Detector, PIR and Exit Sign). The "UV12VDC" can be plugged into an electrical outlet to power the transmitter and camera. An alternative to the "UV12VDC" is an external 12 VDC battery source. We recommend using a 12 VDC rechargeable sealed lead standard alarm battery (e.g., Yuasa, Elk or Powersonic). The external battery makes most sense for applications in a drop ceiling. The battery can be placed just above the unit it is powering. 3. A rechargeable battery is built into surveillance units that can accommodate the battery size (Plant, Day Planner, Binder, Wall Picture and Briefcase). The Day Planner, Binder and Briefcase come with a 5-6 hour battery and the Plant and Wall Picture come with a 10 hour battery. A charger, with automatic float/trickle charge, is also included. The charger can be left plugged in, and the power cord hidden, if continuous operation is necessary. We can supply Powersonic batteries if necessary. A 4-foot cable with a 2.1mm barrel- style plug is installed on all batteries. This plug fits into the power jack of all of our 9-12 VDC Spycameras.