On Nov 5, 5:48 pm, "Peter Crosland" wrote:
I have recently purchased a new digital camera which uses
re-chargeable batteries. I have not used rechargeables for 10
years and have the following questions:

The battery pack says charge for 16-20 hours. Will I damage them if
they stay on charge for, say, 3 days or more ?

That depends entirely on the charger - not battery. So you'd need to
look at the instructions for that. If it obviously switches off after
charging it should be ok.

Wrong! It depends on both. You need to use a charger designed for the type
of battery you wish to charge. For example Ni-Cad cells need a quite
differnt charging patter than say Li-Ion ones.

Well, obviously! We assume the OP has been provided with the charger
appropriate to his cells, in which case all that matters is whether the
charger is designed not to overcharge them.


Is it advisable/necessary to use/discharge the batteries totally
before recharging, or can I recharge them when they are half used.
They used to say that rechargeables developed a "memory" - is that
still true?

It never was. It was a con to persuade you it was your fault batteries
didn't last.

Wrong!

It was not a con at all, but has been repeatedly proven by
experiment. Ni-Cad cells are particularly prone to this.

Only under very particular circumstances such as spacecraft passing
regularly between night and day where the batteries were regularly
charged/discharged between the same points. It doesn't happen in normal
domestic use. Just google "nasa nicad memory effect".


I've seen advertised charges that will recharge ordinary
non-rechargeable batteries. Are these any good ?

Wrong again!

They do work but not very well. Not a good choice really unless you are
desparate.

No. And rechargeables cost so little more anyway.

Wrong! Unless of course you regard a price difference of at least 50% as
being insignificant.

You have to look at the lifecycle of the cells. Even 100% difference
would be insignificant when you take into account the number and
effectiveness of recharge cycles possible with true rechargeables.

MBQ