U2 Recharge?

[JJH]

I am looking to get a U2 and viewing some old sales posts there seems to be different body versions that will or will not accept rechargeables, and also something about donut holes. Please help a newbie gather his facts before he buys. Is there a new and old version? Recharge good-donut bad-
Thanx

 

[wasBlinded]

Older versions will accept the fat 2600 mAh 18650 Li-ion cell. Newer ones are limited to the thinner 1600 mAh 17670 Li-ion cells. They both work fine, one will just have a shorter runtime.

Due to the nature of the Luxeon V 2x2 die, when the U2 is in best focus there will be a slightly darker area in the middle of the hotspot. This seems to vary from sample to sample. It seems to irritate some people to no end, but those are usually the ones for whom the light is a plaything more than a tool.

 

[JJH]

Older versions will accept the fat 2600 mAh 18650 Li-ion cell. Newer ones are limited to the thinner 1600 mAh 17670 Li-ion cells. They both work fine, one will just have a shorter runtime.

Is there a way to tell which light you are getting if you buy used. That's a pretty big power difference.
Thanks