It’s standard in the sense that a 18650 with a protection PCB on top and both poles on the same end isn’t exclusive to this manufacturer and others use it. Ther

It’s standard in the sense that a 18650 with a protection PCB on top and both poles on the same end isn’t exclusive to this manufacturer and others use it. There is nothing proprietary about it. But it’s not run of the mill 18650 either. But it’s rare enough that it’s hard to find. So much so that it actually doesn’t make economical sense to find this (rare, at a premium) variant because it would cost about as much or more than a new light (which includes new batteries, ironically)