Ok, I asked this in another thread but how many different versions have there been? Just one? I have no idea which one I have (bought from Nashbar recently); it has no markings on it whatsoever.

To my knowledge, they have only had one version of the taillight.

There are 2 versions that I know of, the AA-Nickel Metal Hydride version, and the Lithium-Ion version. They have the same output & pattern, however have different voltages and software.

There are 2 versions that I know of, the AA-Nickel Metal Hydride version, and the Lithium-Ion version. They have the same output & pattern, however have different voltages and software.

Good point. I was thinking more in terms of generations/LED bulb technology and assumed everybody knew about the different series/batteries.

By software do you mean the Li-ion battery strap that fits into the slots in the battery instead of the AA pouch and new seat post mount; or the internals of the light; or all of the above?

Software--the instructions that tell the processor inside the light what to do in different modes and also for voltage regulation and monitoring. The regulation/monitoring would be slightly different between battery types.

^^^ As stated.

there was also I think a rev 1 of the taillight...maybe I am wrong. it was the same power but perhaps a different blink logic...and different canister. but essentially the same light

Yeah...some of the videos I've seen on youtube seem to have the blink mode be full off/on, instead of leaving it in a lower light mode between flashes.

For example:

Not on between flashes
http://www.youtube.com/watch?v=tO5pSLL4e7E
On between flashes
http://www.youtube.com/watch?v=hncak2gbDOY

In the first video the flashes also appear to be closer together.