I bought 12 of these thinking I would be able to see my guylines in the dark but I have tested them and they don't even glow for a half an hour! I used my 3 cell Mag Light that I converted to l.e.d. (extremely bright)to charge them. Charged them for about 30 seconds, stuck them in my backpack (it was daylight) and came back 30 minutes later and they were not glowing at all!
Needless to say, I am very disappointed! Anybody having any luck with these things? I will say that they are great for adjusting guylines but I might as well have gotten the black ones. Oh well, you live and you learn I guess.