Bringing this one back from the dead for a related question. I did find a charger for it, but after using it a while, I'm not sure how to interpret the charging LEDs. There are two on the back of the light: a red one and an amber one. Normally, neither is lit. When I plug the charger into it, the amber one lights solid. I think it's a safe bet that is the 'Charging' light. I'm able to occasionally get the red one to flicker if I have the charger plugged in and turn the light on and off real quick. But other than those 2 things, I've never seen the charge LEDs do anything else.
A full recharge is supposed to take 3 hours. I've charged it for a few hours, but I've never hit the 3 hour mark. Given that I had to buy an aftermarket charger, I've never left it unattended while charging so I've had to unplug it before getting to 3 hours. Astro's documentation is short, though not terrible, but it never mentions the charge LEDs.
All that said, those of you own 12SLs, how have seen the charge lights to work?