| Author |
Message |
ian
Guest
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 Posted:
Sat Dec 18, 2004 11:51 pm Post subject:
nimh battery chargers |
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Does any have a circuit diagram for a proper battery charger, for AA
nimh batteries.The usual rubbish that comes with them never gives the
capacity of the battery |
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xx
Guest
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| Posted:
Sun Dec 19, 2004 8:10 am Post subject:
Re: nimh battery chargers |
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Ian,
I don't have any schematics to share with you, but I do understand that the
Maha brand chargers are quite good. They seem to use a combination of
negative delta V and temperature sensing to determine the state of charge
and when to shut down the charging process. Personally, I would avoid any
of the super fast chargers. Maha chargers are sold by Thomas distributing
which you can easily find with a search. I found it frustrating that the
many other charger brands (everyready, sony, et al) that I have looked at
give virtually no info on their charge sensing methods.
"ian" <pb014d3394@blueyonder.co.uk> wrote in message
news:L__wd.30994$Rf4.17534@fe2.news.blueyonder.co.uk...
| Quote: | Does any have a circuit diagram for a proper battery charger, for AA nimh
batteries.The usual rubbish that comes with them never gives the capacity
of the battery |
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| Back to top |
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Roy Lewallen
Guest
|
| Posted:
Sun Dec 19, 2004 4:06 pm Post subject:
Re: nimh battery chargers |
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I've had mixed success with Maha chargers. One problem has been that
with NiMH cells they'll often end the charge long before it's complete.
Except with the models that tell you how much charge they've put into
the cells, you won't know this has happened unless you're aware of the
initial state of the battery and about how long it was charging. It can
give you a nasty surprise in the field when one or more cells go dead
after delivering only a small fraction of their rated charge.
This is mostly a problem with new cells, until they've been cycled fully
a half dozen times or more. Maha chargers aren't the only ones that do
this, but I've had more trouble with them than most others.
I also don't trust the Maha chargers with AAA cells (although I realize
that's not directly the subject under discussion) since the first time I
tried charging AAA cells with my 777+ it overcharged them to the point
they vented. The charger was still operating when I pulled the
batteries, which were nearly too hot to touch. Yes, I did have the
magnetic temperature sensor in direct contact with one of the cells.
Roy Lewallen
xx wrote:
| Quote: | Ian,
I don't have any schematics to share with you, but I do understand that the
Maha brand chargers are quite good. They seem to use a combination of
negative delta V and temperature sensing to determine the state of charge
and when to shut down the charging process. Personally, I would avoid any
of the super fast chargers. Maha chargers are sold by Thomas distributing
which you can easily find with a search. I found it frustrating that the
many other charger brands (everyready, sony, et al) that I have looked at
give virtually no info on their charge sensing methods.
"ian" <pb014d3394@blueyonder.co.uk> wrote in message
news:L__wd.30994$Rf4.17534@fe2.news.blueyonder.co.uk...
Does any have a circuit diagram for a proper battery charger, for AA nimh
batteries.The usual rubbish that comes with them never gives the capacity
of the battery
|
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