Re: Utility Rechargeable flashlight for my mate\'s house.
I just bought the Craftsman Xenon Ultra-Beam Lantern, not so much for emergency use as to have something bright that ran longer than the Mag charger. Shame they lied about the 4 hr. runtime, I just can't believe it'll get that off a 4AH HiWatt Gel SLA. Could always swap in a 5 cell Krypton I suppose. They overcharge for the Xenons - $7 for a 2 pk. RS used to carry 6V 1A Xenons but no more. I used one in a bicycle light mod, a Road Toad 4AA with an external 6V camcorder batt. pack. It took the heat, which is pretty impressive.
Biggest ***** about the Ultra-Beam though is that the internal charger is a LM317 circuit (typical, w/current limit) set to 7.2 volts. IOW, they're right when they say in the manual, don't leave on charge over 36 hours. So much for leaving it float charging so it's always ready. Then again, the batt. should hold 80% charge over 6 months according to
http://www.hiwatt.com.hk.
Well, if I end up caring enough I can always get a PowerSonic PSC-6500A (for as much $ as the Ultra-Beam itself) and short out the internal regulator. I think it'd be OK if I just ran a wire from + input to the batt. side of the diode they have on the charger output. Dunno what would happen if I used the charger side of that diode, might confuse the PSC, might damage the LM317? I would think a linear regulator would just shut down if you shorted the output to the input but am not sure.
Most of its internal circuitry (3 transistors & a zener) is for the battery meter....which, I hope works better than the one on the rubber 4D lantern I also bought ($13). Nice concept, but it goes yellow at 3.2V, which is well below what I'd call "50% life left". After that it dims so much it's hard to see and it's fully red (green goes out slowly) at 2.6V, which is supposed to be "25% left". Yeah, right.
Oh well, nice rubber lantern in other respects, and the LED at least says, if the light doesn't come on, whether it's your batts or your bulb that are shot.