The type of battery you should use depends on the wireless security camera system. If your system utilizes a PoE (Power over Ethernet) setup, then you’ll need to power the cameras via DC Power Adapter – such as this one made by Planet. Depending on your budget and how long you want to run the cameras for between charges, we suggest using rechargeable batteries even if they’re not Lithium-Ion or Li-Polymer; they can be recharged in an inexpensive charging device instead of spending a lot more money down the road when buying disposable batteries for regular use. The two most popular types used are Nickel Cadmium (NiCad) and Nickel Metal Hydride (NiMH). We prefer NiMH over NiCad when they’re available because they have no Cadmium which is a hazardous heavy metal that poses risks to humans and our environment. This type of battery should be recharged when the camera system shows low battery power just like any other rechargeable battery you use.