Decoded battery is non-original, third part manufactured battery that doesn't have Canon's microchip for tracking charge and number of shots taken, but otherwise behaves and acts just the same (i.e. charges on Canon original charger, and shows the remaining charge capacity on the LCD screen).

Do I need a spare camera battery?

A spare battery is one of the most essential camera accessories to have in your bag – particularly if you are traveling, or shooting a long event such as a wedding. Most serious photographers will have at least a couple of spares in their camera bag.

How do you take care of a camera battery?

The battery should be stored in a cool location with an ambient temperature of 15 °C to 25 °C (59 °F to 77 °F; avoid hot or extremely cold locations). Charge and discharge the battery at least once every six months. Turning the camera on or off repeatedly when the battery is fully discharged will shorten battery life.