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Geoffrey S. Mendelson Geoffrey S. Mendelson is offline
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Default 9v battery terminal blanks?

Peter Hucker wrote:

Then use the new type of NiMH, the pre-charged ones which don't lose
power sat on the shelf. Take them out the packet and they are as good as
alkalines. Only keep them for a fraction of their life if you want a
nice long charge, and put them in a trickle charger when not in use.



There are three problems with them. The first is that they are supplied
charged, but only about 80% charged. While they take longer to discharge
on their own, if they sit on the shelf for a year or so, they very well
may be flat.

The second is that they do not reach their full capacity when recharged
until they have been through 3 or 4 recharge cycles. I have found with
the ones I bought it took even longer, sometimes 10 cycles to get
any useful life out of them.

The third is that they have a higher internal resistance which limits their
output current. That is why the rechargeable alkelines that came out around
1995 never really took off. They were lower in capacity to the disposable
ones (about 80%) to allow room for expansion, and they did not put out
the current that nicads or regular alkelines did.

They also do not charge as fast. I charge mine in a 7 hour NiMH charger,
but have to do it twice. Using the little fixed rate charger that came
with a set, I have to charge then for at least 24 hours.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM