On Fri, 06 Nov 2009 10:56:35 +0000, Timothy Murphy wrote:

But I was wondering what it mean if you get a flashing red light when a battery is inserted. Does it mean that the battery is useless?

It means the charger isn't happy about that battery. Had it this
morning on one from a set of three AAA's. Took it out, counted to
ten, put it back in and it was happy.

Consistent flashing red would indicate a battery that really is "past
its best". Before rejecting a battery as truly dead I'd use a normal,
simple, constant current, charger for an hour or so then try the
clever one again.

--
Cheers
Dave.