Vortex3 wrote:

A second application would be use with a lead lamp when doing electrical
wiring at the fuseboard with all power off, in the half-light and with a
torch in your mouth!

If this is an important usage for you, make sure the UPS has (both
in the advertising blurn *and* in practice - says the once-bitten
twice-shy buyer here!) the "cold start" facility - i.e. that you can
make the thing produce the magic 240VAC when you hit the "on" switch
without having it plugged in to a live 240V supply. You may find the
one you're looking at is happy to take over when a load is being drawn
and the supply fails - the standard usage for a UPS - but that it won't
start up all on its lonesome...

Where Andy H has a fixed "emergency light" by his fusebox, I have a
lead-acid rechargeable flourescent torch fed by a wallwart charger,
which comes on when the wallwart is unplugged or if its supply fails.
I got it about 10 years ago from an electrical trade counter, and they
still seem to be sold at such places and by the on-line equivalants (TLC
and the like).

Stefek