Batteries and power for your camera
All cameras can be powered via a mains connection or using a detachable battery. Camcorders have a built-in signal in the viewfinder, which will tell you if the battery is running low. If you use an LCD screen or an external mike without its own battery, you will use more power. Always make sure your battery is fully charged when preparing to film, and take an extra charged battery, and if possible, adapters that will enable you to charge your camera batteries from an automobile or other 12-volt power source.
Most batteries are now lithium/ion batteries. They do not need to be completely discharged before recharging.