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.