HP Forum Archive 14

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US Supplier for n-cell rechargeables? Message #1 Posted by Gene on 4 Nov 2004, 12:17 p.m. Anyone have a link to any website where N-cell rechargeables are still sold? Is there anyone on ebay that is selling these? I have seen a seller on ebay who is selling rebuilt HP rechargeable HP41 battery packs (and has replaced the original nicads with nimh batteries), but I'd like to find some individual n-cell rechargeables. I had some Radio Shack batteries, but I don't think they sell them any more. Any link to someone who is still selling these would be appreciated. Thanks, Gene

Re: US Supplier for n-cell rechargeables Message #2 Posted by Katie on 4 Nov 2004, 12:52 p.m., in response to message #1 by Gene The Nicad Lady sells Sanyo N-size nicads: http://nicdlady.com/cell_pr.html#nicads

Thanks, Katie...looks like Radio Shack in Canada still carries the rechargeables Message #3 Posted by Gene on 4 Nov 2004, 2:01 p.m., in response to message #2 by Katie http://www.radioshack.ca/estore/Product.aspx?language=en-CA&catalog=RadioShack&category=Ni-MH+Batteries&product=2300521 This is roughly $8 (US) per 2 battery set. Alkalines don't last that long if you're running the NoVRAM module, a card reader, etc. And, rechargeables will last a pretty long time. :-)

Re: US Supplier for n-cell rechargeables? Message #4 Posted by Garth Wilson on 4 Nov 2004, 12:52 p.m., in response to message #1 by Gene Try www.nicdlady.com . I see them at local electronic swapmeets. They can rebuild battery packs too and you may not be able to tell it from a factory job. It seems like we keep going through this on the forum though. Why would you want rechargeables? A set of alkalines probably lasts me 2-3 years, with no attention to having to recharge them. It's so much easier. If you have a card reader, that takes a lot of current, but for such short periods of time that I wouldn't expect it to have a significant effect on battery life.

Re: US Supplier for n-cell rechargeables? Message #5 Posted by chas on 4 Nov 2004, 10:12 p.m., in response to message #4 by Garth Wilson Never had a nicad leak! Never had a set of alkalines last 6 months. My 41cv just passed it's 26th anniversy with uncorroded contacts.

Re: US Supplier for n-cell rechargeables? Message #6 Posted by Garth Wilson on 4 Nov 2004, 11:55 p.m., in response to message #5 by chas Just replace the alkalines (all of them at once) when the low-battery indicator comes on, and they'll never leak either. My 41cx is almost 20 years old and in perfect condition. You'd have a hard time telling it from a brand new one (if brand new ones exited). It has probably been through 15-20 sets of batteries, although many of those were when the 41 was being used 8 hours a day for controlling automated test equipment and a set of batteries lasted maybe a month. I had to put instructions in the program to test the batteries (flag 49) and make the calculator give a message and turn itself off if they were low because the production operator would otherwise run them down until it wouldn't work anymore and it would start losing its memory. I used to hate the fact that the tape drive was not made to take alkalines. With the rechargeables, you couldn't leave it unattended with the 41 logging data and go more than half a day on one charge. With alkalines you could probably go a couple of days if they were an option.

Re: US Supplier for n-cell rechargeables? Message #7 Posted by unspellable on 5 Nov 2004, 10:06 a.m., in response to message #6 by Garth Wilson My HP28S goes for a long time on a set of three alkaline N cells so I wouldn't monkey with rechargables. On the other hand, I have some flashlights that use N cells and rechargables would be nice in that application. They use LED's and I am wondering about how compatible the internal resistance of a rechargable would be. I suspect the LED's are using the internal resistance of the alkalines as part of the ballast resistance.

Re: US Supplier for n-cell rechargeables? Message #8 Posted by Dave Shaffer on 5 Nov 2004, 10:51 a.m., in response to message #7 by unspellable re: "I suspect the LED's are using the internal resistance of the alkalines as part of the ballast resistance." I doubt it. If I remember correctly, a single LED needs a current of a few to perhaps a few tens of milliamps. For a 1.5 V battery, if I am playing with LEDs, I put a 100-200 ohm or so resistor in series with the LED. Conversely, the internal resistance of a good battery must be under an ohm, or it wouldn't deliver much in the way of peak current.

Re: rechargeables -- a "zap treatment" testimonial Message #9 Posted by Paul Brogger on 5 Nov 2004, 12:15 p.m., in response to message #1 by Gene If certain rechargeables are hard to find or expensive, you might consider trying the "zap treatment". I just bought a used Makita 12V cordless VSR drill/driver on eBay for parts. It came with two absolutely dead battery packs. These are obsolete and run something like $40.00 each, so I thought I'd give 'em a try. I bought a "slave" flash unit from the local camera store ($20.00, runs on two AAA's) and hooked up wires and my multimeter as described in the article. I disassembled the battery packs, cut away openings in the insulating cardboard tubes, figured out the batteries' connections, and methodically zapped 'em once each, one by one. Worked like a charm! (So far, at least.) I can't yet vouch for their longevity, but the two packs each hold far better charge than do my own original batteries. (They're next.) One thing I did that I won't repeat: For convenience, I usually zapped the batteries by touching the electrodes to the batteries' cases. Since then, I've reflected that I may have weakened the cases and invited premature leaks. (Each zap leaves a little "spot weld" mark.) Next time, I'll do the extra work necessary to touch only the spot-welded metal connectors that hold the batteries together. Anyway, just thought I'd share -- the technique is effective and (more importantly) very satisfying.

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