Does anyone know whether or not rechargeable Nicad batteries can be used in any product requiring batteries (flashlights, radio, etc.)? Thanks.

-- susan (smhakala@aol.com), January 11, 1999

Answers

Nicads can't put out a much current (power). They don't last long on a charge, either.

In practice, the only place I have had trouble is in portable TVs, though.

-- Anonymous (Anonymous@anonymous.com), January 11, 1999.

> Nicads can't put out a much current (power).

Rubbish!

NiCad batteries can put out a HUGE current. Unlike ordinary batteries, (and like a car battery) a short-circuit Ni-Cad can make one heck of a spark -- quite enough to burn you or start a fire. I think this is the reason why many makers of toys say "do not use rechargeable batteries" even though their products work perfectly well if you ignore the advice.

NiCad cells are 1.2V, compared to the 1.5V for non-rechargeables. This will mean that a torch may run a little dimmer, and a radio may distort a bit more on loud. However, in many circumstances the higher current ability more than compensates for the lower voltage.

NiCad cells hold about half as much charge as (non-rechargeable) alkaline cells the same size. They also leak rather fast and go flat by themselves a few months after being recharged. Neither usually matters much because you just charge them again.

You can also get NiMH rechargeable cells. These cost more, hold more charge, don't go flat nearly so fast, and are less of an environmental hazard if landfill-tipped.

-- Nigel Arnot (nra@maxwell.ph.kcl.ac.uk), January 11, 1999.

Indeed they can, in most cases. They won't last as long, so have extras on hand.

I built LED task lights and other Y2k type devices to run off ni-cads, so yes, they do last awhile if you don't abuse them.

-- Bill (billclo@hotmail.com), January 11, 1999.