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Old September 19th 04, 03:07 PM
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On Sat, 18 Sep 2004 23:46:03 -0500, Chris W
wrote:

Peter Duniho wrote:

"Chris W" wrote in message
news:2n73d.69282$mu.28256@okepread07...

if they hare in parallel yes the mAh rating goes up for the pack, but
normally they are in series, so the pack voltage goes up and the mAh
stays the same.



He's asking about charging time, not battery life.



I guess I wasn't very clear was I. If they are in parallel the mAh goes
up and therefor the charging time when charging at a fixed mA rate.
But in series the mAh doesn't go up so the charging time would stay the
same. Of course your charger has to be able to put out a high enough
voltage or the battery will never charge.


This thread is getting confusing!

EACH BATTERY (NiCAD or NiMH) requires to be charged at an equivalent
to 40% to 60% more than their capacity, because they are not 100%
efficient. As you have all the batteries in series you chage at about
1200/200 = 6 hours plus 40 to 60% = 2.4 to 3.6 hours extra.

Personally I would use 40% to 50% since any battery overcharged will
have a shorter life if charged at more than 10% of its rated capacity,
i.e. greater than 120mA in your case. I seem to remember that Nicads
can be overcharged for abut 100 hours as long as you don't exceed 7%
of their capacity rating for charge current. That is not usually an
option these days as many fast chargers have built in sensing to
detect when fully charged.



David

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