On Sun, 4 Jul 1999 19:45:02 -0700, Jan Steinman <Jan@xxxxxxxxxxxxxx>
wrote:
>>From: Frank van Lindert <Frank.van.Lindert@xxxxxxx>
>>
>>On Fri, 2 Jul 1999 13:39:55 -0700, Jan Steinman <Jan@xxxxxxxxxxxxxx>
>>wrote:
>>
>>>>From: "Ron Crabtree" <crabtree@xxxxxxxxxxxxxx>
>>>>
>>>>2. What happens if I charge the batteries for too long a period of time, say
>>>>10 hours or so?
>...
>>>If you want to leave a charger attached for a longer period, you should
>>>either use a charger designed for such use, or a "trickle charger" that
>>>puts no more than about 50mA through the cells.
>>
>>I don't agree with you, Jan.
>...
>>I do agree with you on the trickle charge for prolonged periods. But
>>50 mA is far too much for 120-160 mAh cells (and much more than the
>>Olympus charger can deliver). An acceptable trickle charge current
>>would be about 2 or 3 mA!
>
>Oops! You're right, of course, Frank. For some reason, I was thinking of AA
>cells, for which 50mA would be an acceptable trickle. You should not exceed
>1/10th the ampere-hour rating for trickle charging, so you could go up to
>12mA or so for the "shorty" cells in the Olympus pack, which would charge
>them in about 14-16 hours.
>
>My turn to disagree -- 2 or 3 mA might take as long as four days to
>recharge the pack! In fact, that would barely keep up with the
>self-discharge rate of NiMH cells.
Maybe I should stand corrected for misinterpreting the word 'trickle
charge'...
I have always thought that trickle charging was exactly meant for that
- compensate for the self-discharge. I have a good quality charger
which does either a normal charge at 0.1 times or a fast charge at 0.3
times the ampere-hour rating. After sensing that charging is completed
it switches the current back to 0.03 times the same ampere-hour
rating. I thought that the latter process was referred to as trickle
charging...
Anyway, for the Olympus NICad pack the normal charge current would
indeed have to be at 12mA during 14 hours.
The Olympus charger gives 30 mA which is a poor but acceptable way of
fast charging (4-5 hours), given that you switch it off in time.
A continued charging to compensate for self-discharge should be done
with 2 or 3mA (but this is impossible with the Olympus charger).
Frank.
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