It should really be wired to (or relay interfaced with) local lighting circuits so when the local lighting fails the emer lighting comes on. Even more important with larger installations where one phase could fail.
At work, almost all the lightswitches (MK Grid) have a 'secret key' switch labelled "emer light test"
Owain
Conversion packs enable almost any luminaire to be converted to emergency use.
Owain
Sigh indeed. It's things like this that must change in the coming years.
Measured or what the plate says? I don't doubt you but I'd expect the plate rating will be the full charge consumption rather than any standby charge (if one exists)...
It's not so bad, an extra 1/4 unit/day if you have 2. The way you mentioned it initially I had ideas of 20 or 30W each... Admitedly 5W is nearly 1/2A @ 12v which is huge charging current for standby use.
Measured. (I can't remember if the plate says anything useful.)
When you think how many of them are deployed in commercial and public buildings, it probably adds up to a lot. If they were ever to become common in homes, that would be even worse. I don't actually think much of the 5W goes into the batteries. Both types I have have a large ceramic green wire-wound resistor which runs far too hot to touch. I haven't examined how they operate in any detail, but it might be that when the batteries are flat, more of the power actually goes into them.
Incidentally, these only have one or two cell NiCd batteries. (One cell means you can safely run it completely flat without damage, as there's no second cell which might start suffering reverse charging.)
I've actually got 3 more emergency lights which are home-made. One is integrated into the main light fitting, others stand alone. They run from a central 12V SLA, and being linked to my home automation, they only come on if it's dark outside and the regular light in that location had been on when the power cut happened. The room switch will then operate them instead of the main room light, until mains power is restored.
How about these, look less commercial IMHO
In the end, I measured two models, both long 8W versions. Both discharged until the light went out before the tests began.
The one mentioned before is a TOP LITE LF502, battery dated 2006. This took 14ma =3D about 3.5W regardless of the state of the charge, even after 30 hours which is well above the 24 hours quoted for recharge. Nothing was significantly warm after this time, not even the battery, though the transformer runs slightly warm.
The second, a JSB Zeta II, is slightly older, 2004 on the battery. This started at 36mA =3D about 8.25W and fell to 32mA =3D about 7.5W after
3 hours where it stayed, +/- a milliamp. The manufacturer's leaflet says it takes 8W. The battery didn't get warm, but there is a big green resistor that runs too hot to touch whether charging or fully charged.This is a bit of a surprise, as you'd really expect the current to drop to almost nothing once fully charged, running only the (admittedly bright) LED. If Nanny decides every home has to have several, it'll make quite a hike in the national carbon footprint!
I note that the batteries say they should be replaced 4 years after putting the lamp into use, which further increases the cost of ownership. But I doubt if anyone in a domestic situation will take that seriously as long as they keep going when you test them for longer than you think you'll need to get out/find a torch.
I conclude that if you really feel you need emergency lighting in a house it would be cheaper to have some battery-powered lights screwed to the wall at strategic places, as long as you remember to check the batteries regularly. Unlike commercial premises where there are often visitors, the family will know their way around well enough to feel their way to the light in the dark. Or you could use a sound-activated "clap" light.
Chris
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