As luck (or lack thereof) has it, the following happened to me with one of these just today:

I bought on of these no-name lights from Amazon over a year ago (the ad looks identical to what I remember, including the the stripes on the cable in the picture) because my Niterider light needed a warranty repair, and I used it as a backup. So, Niterider needs another repair, so I sent it off, and I pulled this light out of the drawer to use in the interim.

The battery had a charge, and the light still turned on; so far so good. I plugged in the charger and charged the battery, and the little charge light turned green. My only worry so far is how long the battery will last. Then I pulled the charger from the socket, and discovered the that right at the base of the charger cord, the wire insulation had pulled completely away from the charging unit, exposing a couple of millimeters of bare copper wire. I have no idea how this happened, as the charger had barely been used, and I'm amazed that the whole thing hadn't shorted out during the charging.

So in my case, these no name lights looked like they would serve as a cheep backup light, but in practice, not so much. The light seems to work, but I can't charge it (it hardly seems worth risking an electrical fire). So what to do? Do I buy yet another one, and hope for better luck? Do without without a light for a couple of weeks until my Niterider comes back? But another flimsy charger (they do seem to be available on Amazon)? I'm not out a lot of money, but the thing that was supposed to help solve another problem has turned into it's own headache.

I think I had bought yet another of these before I got a Niterider, but returned it because the battery would last barely an hour. Some people seem to report having luck with these, but it seems like complete luck of the draw. Mine failed with very little use right when I needed it.

This thread appeared at the right time, so I took it as a chance to share and vent.