LED torches & batteries
18650 lithium-ion batteries
18650 lithium-ion batteries are ideal batteries for use in a lot of modern torches. The batteries supply a very high capacity, though they are moderately sized. This produces a very long burn time. Additionally, the 18650 batteries can supply a high capacity, i.e., a lot of light!
When do your use 18650 batteries
Choose a torch with 18650 batteries if you use your torch several hours a month.
If you use your torch less than that, you should rather choose non-rechargeable CR123a batteries, because these don't lose their charge.
Torches suitable for 18650 batteries
There are torches which are perfectly suitable for use with 18650 batteries and there are torches which also work on CR123a batteries in addition.