For another $5 or so they sell the same thing with a charger. BUT I have been warned against charging batteries in series so probably better off.
I tested the batteries they show close to 4000 Mah, so not bad.
The switch is defective. It should show green, I have a one cell that does that.
But in the end, so what. Light works just fine, the green switch is just a bonus.
Of course, you can return it to Amazon and have it replaced.
I actually like this light. I find the beam very attractive, pure white, not a hint of blue.
and the narrow beam gives a good focus, the spill is not distracting when you are trying to look at something.