Flashlights with 21700 batteries: for powerful lights

21700 vs. 18650 batteries

The 21700 battery is the successor to the 18650 batteries. A 21700 battery is larger and twice as powerful as a 18650 battery. Like other batteries, they are named after their dimensions. 21700 batteries are 21 mm in diameter and 70 mm long. Please note: a 21700 will not always replace a 18650 battery. That is why you should only use the 21700 battery in flashlights that can handle these batteries.

How do you use a flashlight with a 21700 battery?

It is best if you charge and use this type of battery on a regular basis. Some people say: 'I take great care of my batteries, I hardly charge them!' In case of Lithium Ion batteries this is not a good thing. These batteries will last a whole lot longer if you charge them on a regular basis.