battery backup nightlight question

danny burstein wrote:

that's 90 minutes with the lamp (lightbulb) assembly that comes with it.
Taking a look at a typical one in my apartment building hallway:
it's got _two_ incandescent lamps hooked up. While I can't read their wattage (and can barely make out the nameplate on the setup), they seem to be about fifty watters.
-So.... if you get something like that and unscrew one of the lamps, you'll get 180 or so minutes (actually longer because reducing load by half gives you about 2.2 or so times the life...). Replace it with a 25 watt incandescent and you're up to five plus hours. Use a ten watt compact fluorescent and you're doing great.

Hmmmmmm ... that is something to consider. I have seen some sources of that type of standby light that are fairly reasonably priced -- and, yes, most do come with a pair of lamp heads, as you indicated.
Thank you! Northe

Sorry, I am a latecomer in this thread. I am very confused here.
If you have a battery backup to power a light, that is inefficient.
You can have a 12V light that is powered directly by the battery. With a little bit of trickery, you could have a LED light that uses next to no electricity. Or a 12V halogen light.
That's much cheaper than buying the battery backup and using it where it is not necessary.
What am Imissing here?
i

Ignoramus21666 wrote:

Sorry, I am a latecomer in this thread. I am very confused here.
If you have a battery backup to power a light, that is inefficient.
You can have a 12V light that is powered directly by the battery. With a little bit of trickery, you could have a LED light that uses next to no electricity. Or a 12V halogen light.
That's much cheaper than buying the battery backup and using it where it is not necessary.
What am Imissing here?

Well, I'm not necessarily that concerned about absolute efficiency in this case. I'm basically trying to provide a night light of approximately 190 lumens (equivalent to the present 25-watt incandescent bulb that I'm using) that will continue to operate for several hours during a power failure. Someone else suggested one of the battery packs used for jump starting cars. If I can find one that operates with an appropriate charge controller so it can be continually floated (and doesn't cost a fortune), I'd see whether I can find or put together a 12-volt LED light source of sufficient brightness to run from it. When I bought my current computer UPS (700 VA rating) it was on sale for a pretty good price, and others have said that such a UPS would probably be perfectly happy running a 25-watt load for a few hours.
Anyway, that's the story.
Northe