I like the idea that you could charge it like an ego, or you could swap the battery out, pop in a fresh battery, and put the old battery on a standard charger. It also says it has three voltages - but unfortunately, it doesn't say what. 3.2, 3.5, 3.7 is one thing. 3.7, 4, 4.3 would be something else. I suspect the first is much more likely.
Healthcabin shows this: Voltage: 4.2V (high power level)/3.3V (lower power level)
Which most likely means that its unregulated power, 4.2 volts at full charge and about 3.3v (before the protection circuit kicks in to shut the battery down). It would be nice if they could make it regulated at something like 4.2 or even 3.7-3.9, but it already has a charging/protection circuit so prolly not a lot of room for much more. I forget, are joye eGo's regulated?
I have these ultrafire 3000mah 18650's and the 4.2 volts don't seem to last too long after a full charge. I've had better "quality" vaping time off aw imr 1600mah 18650's. Idk if its that the ultrafire's are older/had more use or that the aw's are just way better, got about 5 of the ultrafires in classifieds bundled with my roughstack. Wasn't really impressed with them. It's all about the "C" rating I guess