Subject:
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Re: Charging batteries
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Newsgroups:
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lugnet.robotics
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Date:
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Tue, 13 Oct 1998 17:39:12 GMT
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Viewed:
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1840 times
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Radio Shack has a quick charger that does AA and AAA NiMH batteries, I think
it was about $25.00. The AAA cells I bought were $10.00/pr.
Rob Trainer
btrainer@home.com
rtrainer@csti-md.com
Alex Wetmore wrote in message <908291583.842286@phred>...
> Eric Brok wrote in message ...
> > Our institution (a school) considers to purchase two Mindstorms sets for
> > students to work with. I'm looking for the best way to deal with batteries
> > in such a setting. I have seen some posts mentioning some concerns, but
> > would like to have some more advice, like:
> > - are NiCad the best and/or only rechhargable batteries
>
> NiMH is also an option. They are coming down the prices of NiCad (about
> $5/cell right now). The average NiMH AA cell has a greater capacity then
> the average NiCad cell (1300mah vs about 850mah).
>
> > - are quick-chargers better or worse; depending on what?
>
> Quick chargers which make some effort to sense the state of the battery are
> much better then slow dumb chargers or timed quick chargers. Its hard to
> find these in AA size though. The only one that I know of is my by Olympus
> for digital cameras. http://www.necx.com sells it (under digital camera
> accessories). Its about $50 including 4 AA batteries, so you'd need 3 of
> them for two Mindstorms robots. It charges 4 batteries in about 2 hours.
> It monitors both cell temp and voltage to determine when to stop charging
> the cells. This makes the cells last much longer, because they never
> overheat.
>
> > - do NiCads have a 'memory effect'?
>
>
> Memory effect is for the most part a myth. 99% of the damaged NiCad cells
> out there were damaged by overcharging them and causing them to overheat.
> For more information on this subject check out the article on battery
> technology at http://www.sheldonbrown.com/harris (its in the set of • articles
> about bicycle lighting). This is a bicycle oriented site, but the article
> is short and good reading.
>
> alex
>
>
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Message has 1 Reply:
 | | Re: Charging batteries
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| Panasonic sells quick-charge high capacity (1100maH) NiCads pretty cheaply. I believe I bought the charger with 4 batteries for less than $20 at Costco, and have bought a few 6packs of AA for less than $15 each ($9-12?) also at Costco. I got them (...) (26 years ago, 21-Oct-98, to lugnet.robotics)
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Message is in Reply To:
| | Re: Charging batteries
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| Eric Brok wrote in message ... (...) NiMH is also an option. They are coming down the prices of NiCad (about $5/cell right now). The average NiMH AA cell has a greater capacity then the average NiCad cell (1300mah vs about 850mah). (...) Quick (...) (26 years ago, 13-Oct-98, to lugnet.robotics)
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