On 20/10/2020 12:45, George Miles wrote:
I have several emergency lights over the stairs etc, which light up
when the mains fails.

But if they only last 4 hours, and the power trips when i'm asleep at
midnight, and fire breaks out at 6 a.m. or i need to get up, they
will be flat.

So recommendations for emergency lights with longer lasting batteries
please?

Emergency lights are specified to last about 3+ hours runtime.
(more than long enough to allow an emergency evacuation)

You would be much better off with an LED torch by your bedside. A simple
modification to bridge the switch with a ~1M resistor or two means you
can even find it in total darkness (and see by it once dark adapted).

I have a couple of emergency lights - one in the kitchen and one in the
dining room since those are the places where being suddenly plunged into
total darkness could be most annoying. I was able to increase the
batteries in them from 1.3Ah to 4.5Ah after a bit of careful measurement
but that was more because it looked like the physical enclosures had
been originally designed to take the larger batteries.

--
Regards,
Martin Brown