"Dave Plowman (News)" wrote in message
...
I want to fit a battery backup to a small audio device. Something that
will charge a 7.2 volt Ni-Cad pack without damage no matter how long left
on and run the device at the same time - and switch over automatically if
power fails. Maximum consumption of the device is about 250 mA.

There appear to be 'millions' of supervisory chips out there and I was
hoping someone could recommend one.

The SAB module from a burglar alarm bell will do the job, usually costs
under a tenner.

Rgds

Andy R