looking for light fixture with battery backup

I have been trying to find a light fixture with a battery backup to use in a storm shelter. I would like to have a light that would continue to operate even if the power goes out. Does not have to be extremely bright because it is a small room, 6x6. I don't think it would be that difficult to make one, but would think there would be a off the shelf item available.

I assume I could take a 12v power adapter, a 12v battery pack and some 12v LED lights together and it would work, but It would be nice to have a manufactured version instead of a cluster of wiring mess.

So does anyone know of a light that I can use off of 110 until the power goes out, then it switch over to a backup battery?

Thanks

Maybe not quite what you are after, but I've got an induction-charged nightlight/flashlight (same as this one - "Click" brand from Bunnings Aus/NZ), it cost about $20; if mains-powered (well, charging) it acts as a sensor light, not sure if you can bypass to make it capable of turning on/off manually. When out of it's charger, it uses it's battery, toggle between off/panel-light/torch (aka flashlight). We use it in our baby's room for when we're putting him to bed, if you leave it on for a few hours a night it might need a recharge every week or two. Induction charger seems to get hot if you leave it on for a long time though, I don't like that, doesn't seem to have a cutoff.

Same principle but different manufacturer on alibaba, to get more of an idea: link

Or a quick search on ebay came up with this sort of thing, don't know if I'd trust it, but gives you some places to start looking.

RoGuE_StreaK said:

Or a quick search on ebay came up with this sort of thing, don't know if I'd trust it, but gives you some places to start looking.

Click to expand...

I have seen these on dealextreme, I might buy one for testing, but was unsure how reliable they would be.

http://store.axiomled.com/AX_RUDOLPH_50_p/ax-rudolph-50.htm

"... operates as a normal light bulb when power is on and can serve as an emergency back up light or flashlight when power is off. The built in Lithium Ion battery provides 5-7 hours of light when the power is off.
... extension arm to turn the light bulb into a flashlight.

Sounds good, except for the "unscrew your lightbulb and turn it into a flashlight"; surely they could have come up with a quick attach/detach system? Also not too useful if it's ceiling mounted and you've got a standard-height ceiling, have to fumble around for a ladder and climb in the dark...

The thing I'm sceptical about with all of these rechargeable bulbs is the charge system; is it smart enough to completely switch off when the charge is finished? Though I guess it only charges when you've got your lightswitch on, depends on whether it's a light you keep on all the time or only use for a few hours here and there?

From the several mentions I've seen here on CPF very few (none ?) of the "always-on-charge" lights have a charging system smart enough to keep the batteries in good condition. In fact pretty well all the "mains & battery emergency" lights I've read about failed in a very short time after the power went off, due to the batteries being damaged by the supplied chargers.

I'd suggest separate battery powered lights and enough lithium primary batteries to cover the maximum expected outage (+50% for a respectable margin of error). Check that they work every 6 months and replace the batteries with new (freshly manufactured ones) every 5 years and you have a very reliable, practical solution.

If finding the lights to switch them on in the dark is an issue either add a tritium marker tube to each light, or add place a PaLight "Survival" light so you can easily see it's long running "Locator glow" (hint the unjacketed Ultralife lithium batteries will fit a "Survival" model and last much longer than alkaline batteries).

Maybe more than you're looking for, a Xantrex power inverter. It's basically a battery in a box with a DC -> AC inverter. It's all mounted on its own dolly, you roll it where you want it. I got mine used (they're pricey new) put in a deep cycle car battery, it sits trickle charging in in the back of the basement. If I need power I've got maybe 80 amp hours sitting there waiting for me.

For a lower cost, try something like this on eBay, switch the light heads over to LED, maybe set it up so a tiny "find-me" light comes on automatically if power fails and there are larger light head(s) that you turn on as you want them.