I charged up the NiteSites last night with a 3 cell Maglight for about 45 min. This was about 9 PM, the dots were very bright. This morning, the dots still glowed but not too bright. Looks like you have to recharge every day.
This a a quote from the NiteSiter web page. "The good news is, 10 minutes of sunlight, 20 minutes of close lamp light, or 5 minutes of Ultraviolet light is all it takes to provide many hours of luminosity". I'll probably figure out which handgun I want to put them on and try them out.
So far, looks pretty good but time will tell.