I remember them being on sale with coupon but never free. The orange & black Thunderbolt alkalines aren't too bad, though they don't have the capacity for higher draw items like a camera. OK for remotes, flashlights, clocks, portable radios, etc. Don't think I've ever had one leak.
Have they put stronger magnets on them now? Ones I have will barely hold the weight of the light, don't directly fall off, but will work their way down whatever you attach them to. Most of the ones I have use the individual LEDs, not the newer ones with the COB ones.