From uwm.edu!spool.mu.edu!agate!stanford.edu!leland.Stanford.EDU!news Fri Nov 13 14:26:07 CST 1992
\nArticle: 8049 of comp.sys.laptops
\nNewsgroups: comp.sys.laptops
\nPath: uwm.edu!spool.mu.edu!agate!stanford.edu!leland.Stanford.EDU!news
\nFrom: avery@scruffy.neuroinformatik.ruhr-uni-bochum.de (Avery Wang)
\nSubject: Re: NiCad batteries again — useful hints
\nMessage-ID:
\nSender: news@leland.Stanford.EDU (Mr News)
\nOrganization: DSO, Stanford University
\nReferences:
\nDate: Fri, 13 Nov 92 09:24:39 GMT
\nLines: 111<\/p>\n
Here’s something I pulled off the net over 4 years ago — hope it’s useful!
\n-Avery
\n——————-
\n” NICAD BATTERIES – FACTS AND FALLACIES ” Published on Radio Communication
\nMay 1988, TT.<\/p>\n
Richargable nickel cadmium batteries, have, with reasons, become a popular
\nsource of power for portable and handportable equipment. They can provide
\nreliable service over many years if due account is taken of their
\npeculiarities. Yet it remain true that many amateurs are failing to appreciate
\nnot only the full capabilities but also the limitations of nicad cells used in
\nbattery packs.<\/p>\n
J.Fielding,ZS5JF,in “Nickel cadmium batteries for amateur radio equipment”
\n(Radio ZS september 1987,pp4-5) provides a useful survey of the facts and
\nfoibles of nicads.The following extracts from his article attack some of the
\ncommon myths and also provide some safety hints.<\/p>\n
1) “Rapid charging causes a decline in cell capacity”.
\nNOT TRUE provided that the charge is always terminated at a safe point.<\/p>\n
2) “You should not charge only partially discharged cells as this causes a
\nloss in capacity.”
\nNOT TRUE. It is not necessary to discharge fully nicad batteries before
\ncharging. In fact, THE OPPOSITE is true. Repeated partial charging gives an
\nincrease in the number of charge\/discharge cycles compared with
\nfull-discharged cells.<\/p>\n
3) “White crystals growing on the tops of nicad cells mean that the seal is
\nfaulty and the cell should be scrapped.”
\nNOT TRUE. The electrolyte (potassium hydroxide) is extremely searching and can
\npenetrate the seals used in minute quantities. These crystals are potassium
\ncarbonate, which is harmless and can be removed with soap and water. The
\naction of the carbon dioxide in the atmosphere reacts with the electrolyte to
\nform the crystals. After removing the crystals, it is recommended that a smear
\nof silicon grease is applied to slow down the growth of new crystals. The
\namount of electrolyte lost in this way is insignificant.<\/p>\n
4) ” I have a cell which appears to take a charge, but after the normal
\ncharging period the open circuit voltage is very low. I have been told I
\nshould throw it away.”
\nNOT TRUE. The reason the cell won’t take a charge is usually due to minute
\ncrystalline growth across the internal electrodes, caused by prolonged
\nstorage. A cure that nearly always works is to pass a very high current for
\nvery short time through the affected cell. This fuses the internal “whisker”.
\nDischarging a large electrolytic capacitor is one method of doing this. But
\nnote that in a battery the faulty cell MUST be isolated from the other cells
\nsince zapping the complete battery will not usually result in a cure. Charge
\nthe capacitor to about 30v and then discharge it through the faulty cell.
\nSeveral attemps may be required to clear a stubborn cell.<\/p>\n
5) “A battery contains a cell with reversed polarity. The only cure is to
\nreplace it”.
\nNOT TRUE. The reversed cell ca usually be corrected by a similar technique as
\nthat given for 4). After re-polarising the cell, the complete battery can be
\nrecharged in the normal way. Full capacity can be regained after about five
\ncycles.<\/p>\n
6) “A nicad battery should be stored only in a discharged state”.
\nNOT TRUE. It can be stored in any state of charge. Due to its inherent
\nself-discharging characteristics it will eventually become fully discharged
\nafter a sufficiently long period of storage. To recharge the battery before
\nreturning it to service, a “conditioning” charge of 20h at the normal charging
\nrate is recommended. Afterwards charge normally; full capacity can again be
\nexpected after about five cycles.<\/p>\n
7) “It is not advisable to keep a nicad battery on permanent trickle charge as
\nthis causes permanent degradation of the cells”.
\nNOT TRUE. So long as the trickle charge current is adjusted correctly, the
\ncharge can continue indefinitely without loss in cell capacity. The safe
\ncurrent can usually be obtained from the manufacturer’s data, but 0.025C is a
\nreasonable guide (ie. about 100mA for a 4Ah cell and PRO-RATA). This enables
\nthe battery to remain fully charged.<\/p>\n
ZS5JF also lists seven safety points that should be considered by users:<\/p>\n
1) DO NOT short circuit a fully-charged battery. This if prolonged, can cause
\nexcessive gas production with the danger of possible rupturing of the sealed
\ncase.<\/p>\n
2) Nicads contain a caustic electrolyte: this is perfectly safe as long as
\ncommon sense is used in use and handling of the cells.<\/p>\n
3) A nicad can supply a very high current for a short period (a 4Ah cell can
\nsupply over 500A for a few seconds). Sufficient thought should be given when
\nselecting a fuse between the battery and the equipment. The connecting wire
\nshould be capable of passing enough current to ensure the fuse blows quickly
\nin the event of a short circuit.<\/p>\n
4) DO NOT use partially-discharged cells with fully-charged ones to assemble a
\nbattery. Assemble the battery with all the cells discharged and then charge
\nthem as a battery.<\/p>\n
5) DO NOT carry a fully- or partially-charged battery on an aircraft without
\ntaking proper safety precautions. A short-circuited battery pack ca be a time
\nbomb in such situations. Consult the relevant IATA regulations or ask at the
\nairline check-in.<\/p>\n
6) DO NOT subject battery packs to very high or low temperatures. Never
\ndispose of a battery pack in a fire or throw it out with domestic waste.
\nIf it cannot be disposed of properly it is probably best to bury it in the
\ngarden in a safe spot.<\/p>\n
7) DO NOT discharge battery packs below about 1V per cell, otherwise there is
\na possibility of cell reversal.<\/p>\n
ZS5JF provides a good deal of other information on charging nicad batteries,
\nand gives as a reference a Varta publication of 1982 “Sealed Nickel Cadmium
\nBatteries” from which some of his notes may have been derived. (G3VA)<\/p>\n
—-=====***=====—-<\/p>\n
From uwm.edu!wupost!decwrl!csus.edu!netcomsv!mork!brunette Mon Aug 10 23:18:11 CDT 1992
\nArticle: 9997 of rec.models.rc
\nXref: uwm.edu rec.models.rc:9997 sci.electronics:38540
\nNewsgroups: rec.models.rc,sci.electronics
\nPath: uwm.edu!wupost!decwrl!csus.edu!netcomsv!mork!brunette
\nFrom: brunette@netcom.com (Hal Brunette)
\nSubject: Re: How to dispose of NiCads?
\nMessage-ID:
\nDate: Tue, 28 Jul 92 20:10:45 GMT
\nOrganization: Netcom – Online Communication Services (408 241-9760 guest)
\nReferences:
\nLines: 88<\/p>\n
>|> D.C. Myers, “Zap New Life into Dead Ni-Cd Batteries,” Popular Electronics,
\n>|> July 1977, pp. 60-61.
\n>|>
\n>|> The article explains internal shorts and how to clear them.<\/p>\n
>If it`s possible, try to rewrite the article in a message here in rec.models.
\n>rc and sci.electronics.
\n>
\n>I`m sure many readers here has many NiCd cells they want to restore. <\/p>\n
The failures the article talks about occur in mutli-cell Ni-Cd battery packs,
\nand are due to the voltage differences between cells. Say you have four 1.25 V
\ncells in a pack connected to a 200 ohm load. The load “sees” 5 volts and draws
\n25 mA. Since each cell must pass the entire 25 mA and each cell’s potential is
\n1.25 volts, Ohm’s Law tells us that each cell sees the equivalent load of 50
\nohms.<\/p>\n
But in practice, no four cells in a battery ever exhibit exactly the same output
\nvoltage. Assume that one cell is delivering only 1.2 V, and the others are at
\n1.25 volts. Now, the 200 ohm load sees 4.95 volts and draws 24.75 mA. Since
\nall four cells must pass the entire 24.75 mA, each of the strong cells at 1.25
\nvolts sees an equivalent load of 50.5 ohms; the weak cell sees only 48.5 ohms.
\nThe weak cell works into the heaviest load and as a result will discharge more
\nrapidly than the other cells. If the pack is charged for only a short period
\nof time, the weak cell, which has been working the hardest, is also the one
\nthat receives the least charging power.<\/p>\n
This usually doesn’t matter if you trickle charge after each day of flying.
\nThe inequality is small for any given charge or discharge cycle, due to the
\nrelatively flat output voltage NiCd cells exhibit over most of their range.
\nBut a combination of incomplete charges and deep discharges will exaggerate
\nthe energy difference between a weak cell and the other cells. Operated
\ncontinually in this manner, the weak cell invariably reaches its “knee,” the
\npoint at which its voltage decreases sharply, long before the other cells
\nreach the same point.<\/p>\n
Now comes the problem! Suddenly, the weakest cell sees an increasingly heavy
\nload, which causes its voltage to drop even faster. This avalanche continues
\nuntil the cell is completely discharged, even as the other cells continue to
\nforce current to flow. The inevitable result is that the weak cell begins to
\ncharge in reverse, which eventually causes an internal short. Once an
\ninternal short develops, recharging the cell at the normal rate is
\nfutile. The short simply bypasses current around the cells active materials.
\n(Even though the cell is apparently dead, most of its plate material is still
\nintact.) If the small amount of material that forms the short could be removed,
\nthe cell would be restored to virtually its original capacity once again.<\/p>\n
300 ohm Charge
\n 5W \/ Switch
\n20-40 + O—\/\/\/—-o——o o————o————————-o
\nVDC | | |
\n | Zap | |
\n | Switch | +|
\n | ___|___ | ———–
\n o——o o———o —–
\n | | + Shorted |
\n 6000 micro- | + ——- Cell |
\n Farad, 40V _________ | | |
\n Capacitor ——— |_____| Volt |
\n | | meter |
\n | | |
\n – O————-o———————-o————————-o<\/p>\n
Using the circuit shown, the internal short can be burned away in a few seconds.
\nIn operation, energy stored in the capacitor is rapidly discharged through the
\ndead cell to produce the high current necessary to clear the short. Current is
\nthen limited by the resistor to a safe charge rate for a small A cell.<\/p>\n
Several applications of discharge current are usually necessary to clear a cell.
\nDuring the “zapping” process, it is a good idea to connect a voltmeter across
\nthe cell to monitor results. Momentarily close the normally open pushbutton
\nswitch several times to successively zap the cell, allowing sufficient time
\nfor the capacitor to charge up between zaps, until the voltage begins to rise.
\nThen, with the toggle switch closed, watch as the potential across the cell
\nclimbs to 1.25 volts. If the potential stops before full voltage is reached,
\nsome residual short remains and another series of zaps is in order. If you
\nobserve no effect whatsoever after several zaps and shorting out the cell and
\ntaking an ohmmeter measurement indicates a dead short, the cell is beyond
\nredemption and should be replaced.<\/p>\n
Once full cell potential is achieved, remove the charging current and monitor
\nbattery voltage. If the cell retains its charge, it can be returned to charge
\nand eventually returned to service. But if the cell slowly discharges with no
\nappreciable load, the residual slight short should be cleared. To do this,
\nshort circuit the cell for a few minutes to discharge it, zap again, and
\nrecharge it to full capacity.<\/p>\n
Good luck.<\/p>\n
From uwm.edu!cs.utexas.edu!sun-barr!olivea!uunet!infonode!ingr!b11!naomi!lester Mon Aug 10 23:19:34 CDT 1992
\nArticle: 10011 of rec.models.rc
\nXref: uwm.edu rec.models.rc:10011 sci.electronics:38596
\nPath: uwm.edu!cs.utexas.edu!sun-barr!olivea!uunet!infonode!ingr!b11!naomi!lester
\nFrom: lester@naomi.NoSubdomain.NoDomain (Les Bartel)
\nNewsgroups: rec.models.rc,sci.electronics
\nSubject: Re: How to dispose of NiCads?
\nMessage-ID:
\nDate: 29 Jul 92 12:42:24 GMT
\nReferences:
\nSender: usenet@b11.b11.ingr.com (Usenet Network)
\nReply-To: lester@naomi.b23b.ingr.com
\nOrganization: Dazix, An Intergraph Company
\nLines: 56<\/p>\n
In article , waeber@ufps9.unifr.ch (Bernard Waeber SIUF) writes:
\n|> In article , brunette@netcom.com (Hal Brunette) writes:<\/p>\n
[Text of ‘zapper’ deleted]<\/p>\n
|> Please correct me if i get this wrong, i guess the above circuit requires
\n|> to remove the dead cell from the multi-cell pack, right ?<\/p>\n
Maybe not, see below.<\/p>\n
|>
\n|> Which means, one has to take the Ni-Cd pack appart, and get the dead cell out.
\n|> The cells are usually connected with a point welded metal plate, which requires
\n|> you to rip the metal plate off the cell.
\n|> Now, once you fixed your shorted cell ( you hope ),with the above circuit ,you will have to
\n|> solder the cell back in place, which isn’t that abvious, if you apply to much
\n|> heat when soldering you may damage the cell, if you don’t apply enough heat you get
\n|> a cold solder spot, in which case it may brake loose, due to vibrations.
\n|>
\n|> The point is : You better know what you’re doing, when trying to recover a
\n|> \t dead Ni-Cd cell.<\/p>\n
Absolutely.<\/p>\n
|>
\n|> \t Guess your plane or heli is worth more, opposed to the 20 bucks
\n|> \t for a new Ni-Cd pack.
\n|>
\n|> So, if you aren’t too confident of fixing your Ni-Cd pack, return them to the place
\n|> where you bourght them.
\n|>
\n|> —
\n|> ben<\/p>\n
You don’t have to remove the cell from the pack (unless it is in parallel
\nwith another cell). Just clip the zapper leads to the terminals of the
\ncell. In fact, it seems to me that it may even work without isolating
\nthe cell if there is a cell in parallel. The shorted cell should take
\nmost of the current, and the non-shorted cell some current as well.<\/p>\n
\t Bad cell
\n\t |
\n\t v
\n ___ ___ ___
\n–|___|—-|___|—-|___|–
\n | |
\n | |
\n | |
\n | |
\n\tzapper leads<\/p>\n
– Les<\/p>\n
—
\nLes Bartel\t\t\tlester@naomi.b23b.ingr.com
\nDazix, An Intergraph Company\tuunet!ingr!b23b!naomi!lester<\/p>\n
From uwm.edu!wupost!cs.utexas.edu!sun-barr!ames!data.nas.nasa.gov!splatter.nas.nasa.gov!bross Mon Nov 16 22:36:07 CST 1992
\nArticle: 8084 of comp.sys.laptops
\nNewsgroups: comp.sys.laptops
\nPath: uwm.edu!wupost!cs.utexas.edu!sun-barr!ames!data.nas.nasa.gov!splatter.nas.nasa.gov!bross
\nFrom: bross@splatter.nas.nasa.gov (Wilson S. Ross)
\nSubject: Re: NiCad batteries again
\nKeywords: Storage, interrupted charging
\nReferences:
\nSender: news@nas.nasa.gov (News Administrator)
\nOrganization: NAS Program, NASA Ames Research Center, Moffett Field, CA
\nDate: Tue, 17 Nov 92 03:55:52 GMT
\nMessage-ID:
\nLines: 9<\/p>\n
My Toshiba battery was force-charged by a friend who has some sort
\nof generic charging equipment. It had reached a point where the machine
\nwould not operate at all with the battery – even plugged in. Now it has
\nremained plugged & working for months, i.e, I have overcome the problem
\nof always shuffling batteries for home use. My other battery (still
\ngood, I hope) sits on the shelf for when I travel. The ‘dead’ battery
\nisn’t good without the power supply.<\/p>\n
Bill Ross<\/p>\n
From uwm.edu!cs.utexas.edu!zaphod.mps.ohio-state.edu!darwin.sura.net!uvaarpa!murdoch!holmes.acc.Virginia.EDU!lch3e Sun Nov 22 15:10:20 CST 1992
\nArticle: 8155 of comp.sys.laptops
\nNewsgroups: rec.video,rec.video.releases,comp.sys.laptops
\nPath: uwm.edu!cs.utexas.edu!zaphod.mps.ohio-state.edu!darwin.sura.net!uvaarpa!murdoch!holmes.acc.Virginia.EDU!lch3e
\nFrom: lch3e@holmes.acc.Virginia.EDU (Lauren C. Howard)
\nSubject: An easy fix for nicads that REALLY works!
\nMessage-ID:
\nOriginator: lch3e@holmes.acc.Virginia.EDU
\nSender: usenet@murdoch.acc.Virginia.EDU
\nOrganization: University of Virginia
\nDate: Sun, 22 Nov 1992 14:38:20 GMT
\nLines: 47
\nXref: uwm.edu rec.video:41091 rec.video.releases:3862 comp.sys.laptops:8155<\/p>\n
Easy FIX for NICADS that REALLY works!<\/p>\n
It’s simple, it’s easy, and it really works well!<\/p>\n
First reinforce the battery pack (if in one) with clear cellophane tape.<\/p>\n
Then drop the battery, onto it’s side, on the floor from about 6<\/p>\n
ft. up. You want it to be a really HARD drop: but don’t break the<\/p>\n
battery. Do this seven or more times for each battery.<\/p>\n
If it’s in a pack, drop the pack so each battery hits the floor seven<\/p>\n
times.<\/p>\n
I know this seems crazy, but it DOES work, and well. If it doesn’t<\/p>\n
work the first time, try again; harder! You have nothing to lose,<\/p>\n
since you’d have to replace the battery anyway.<\/p>\n
An example: the batteries in my portable printer are 8 years old. <\/p>\n
They were at the point where even after 24 hours charge, and still<\/p>\n
plugged into the charger, the printer wouldn’t operate. After<\/p>\n
dropping, I now get three weeks of printing from one charge.<\/p>\n
So far, it’s never failed. What have you got to lose? Post your<\/p>\n
results so others can benefit, and spread the word!<\/p>\n
From uwm.edu!zaphod.mps.ohio-state.edu!darwin.sura.net!gatech!destroyer!news.iastate.edu!sknapp Sat Nov 28 14:31:51 CST 1992
\nArticle: 8219 of comp.sys.laptops
\nNewsgroups: comp.sys.laptops
\nPath: uwm.edu!zaphod.mps.ohio-state.edu!darwin.sura.net!gatech!destroyer!news.iastate.edu!sknapp
\nFrom: sknapp@iastate.edu (Steven M. Knapp)
\nSubject: Re: T1000SE battery replacement (INSTRUCTIONS!)
\nMessage-ID:
\nSender: news@news.iastate.edu (USENET News System)
\nOrganization: Iowa State University, Ames, IA
\nReferences:
\nDate: Sat, 28 Nov 1992 08:37:36 GMT
\nLines: 76<\/p>\n
In article ma90fau@imath1.ucsd.edu (ma90fau) writes:
\n>Sorry if this has been discussed before. On the recent thread,
\n>people has been talking about the Radio Shack’s replacement nicad
\n>cell. For people who has done the replacement for T1000SE, can you
\n>give me the detail instructions(what type of cell to use?..etc) to
\n>revitalize my old battery? …. just trying to find a cheap method
\n>to power my cheap notebook…
\n>Thanks!<\/p>\n
Read me now, or save me for later. (in that imfamous Hans `n’ Frans tone) \ud83d\ude42<\/p>\n
Ok, so you have a T1000SE, and you have found how it does not work if you do
\nnot have a good battery on the back. You called Toshiba, and suddenly felt
\nwoozy. Aftermarket? Shure! $60 for the T1200XE pack (extended life, the only
\nway to go), but there still has to be a better way, the “college student
\nmethod”!<\/p>\n
You call a battery store, and discover that the pack is ‘sealed’ and can not
\nbe rebuilt. Then again, you never did listen to the ‘no user serviceable parts
\ninside’ lables. <\/p>\n
The plan? Open it, replace the cells, and close it up.<\/p>\n
Opening:<\/p>\n
\tIt is sealed, ultrasound welded actually. All you need to do is break
\nthis thin joint. Take the pack off of the computer (back up that hardRAM!) and
\nplace it so that the metal contact squares are faceing you and up. The part
\nfaceing up, or the bottom of the pack, was physically seprate from the rest of
\nthe shell. Note that all 4 metal contact squares are attached to this piece.
\nNow get 2 THIN screwdrivers or knives(jewlers screwdrivers work GREAT). Pick a
\npoint that is faceing you (so it will not show when the battery is
\nreinstalled) and push a screwdriver in the small crack\/seam between the two
\npieces. Continue to CAREFULLY pry apart the rest of the seam, and remember,
\nthe contact squares are comming all together. After having it all opened, make
\nshure to keep the latch and spring (trust me!).<\/p>\n
Replacement:<\/p>\n
\tCall you local battery distrubitor, or Mr. Nicad, or TNR-The battery
\nstore (#’s should be in the 1-800 directory), tell them you got it open. Give
\nthem the measurements of one of the cells. I believe they are 4\/3A 1700mah,
\nand should be about $5 a shot. Mr NiCad does know them as T1000SE cells last I
\nchecked. Get 6 of them. Looking at the old pack, replicate it using the new
\ncells, wire, tape, whatever! DO NOT FORGET THE TEMPRATURE SENSOR! The little
\nblack thing attached to one of the cells in the original pack is VERY
\nimportant! After haveing everything hooked up, you are just about done.<\/p>\n
Close it up:<\/p>\n
\tCheck that the contact squares do have voltage around what you would
\nexpect (5-7.2V). Reassemble the case, and hold it shut however you see fit.
\nSince I use only one pack, having it on the computer holds it together, and
\nmakes it easy to show others my hack. If you have 2 or more, scotch tape
\nshould help, or even super-glue. But be warned, you might want to open the
\npack again some time, and super-glue will make that VERY difficult.<\/p>\n
There ya go! Good luck!
\nAny questions to sknapp@iastate.edu
\nFlames or insults to \/dev\/null!<\/p>\n
I hereby declare this to be advice, use at own risk! I am not responsible for
\nyour actions!
\n________________________________________________________________________
\nSteven M. Knapp\t\t Computer Engineering Student
\nsknapp@iastate.edu\t President Cyclone Amateur Radio Club
\nIowa State University; Ames, IA; USA Durham Center Operations Staff<\/p>\n
—
\n________________________________________________________________________
\nSteven M. Knapp\t\t Computer Engineering Student
\nsknapp@iastate.edu\t President Cyclone Amateur Radio Club
\nIowa State University; Ames, IA Durham Center Operations Staff<\/p>\n
From uwm.edu!cs.utexas.edu!uunet!noc.near.net!news.bbn.com!news.bbn.com!wbe Wed Dec 16 12:28:08 CST 1992
\nArticle: 8462 of comp.sys.laptops
\nPath: uwm.edu!cs.utexas.edu!uunet!noc.near.net!news.bbn.com!news.bbn.com!wbe
\nFrom: wbe@bbn.com (Winston Edmond)
\nNewsgroups: comp.sys.laptops
\nSubject: Very dead T1000SE battery revived
\nDate: 16 Dec 92 03:01:31
\nOrganization: Bolt Beranek and Newman, Inc., Cambridge, MA
\nLines: 87
\nDistribution: world
\nMessage-ID:
\nNNTP-Posting-Host: crystal.bbn.com<\/p>\n
Thanks to suggestions from this newsgroup, and after some experimenting, I
\nseem to have managed to revive a completely dead T1000SE battery pack. The
\nmessage rambles a bit so that others that have experienced the same problem
\nmay compare the solution I found with others that have been discussed in this
\nnewsgroup.<\/p>\n
Completely dead battery = 0V output, 0 Ohms resistance, regardless of how
\n\tlong it was “charged” on a T1000SE.<\/p>\n
Current state = 7.2V output, and it just powered my T1000SE for 75 minutes
\n\tfrom full charge (green light) to first low charge beep, while
\n\trunning the screen at medium brightness and using the 2400 bps modem.<\/p>\n
Yes, 75 minutes isn’t as good as new, but this is the first full
\ncharge\/discharge cycle after revival, so I don’t yet know if it will get
\nbetter with proper use, or get worse again.<\/p>\n
BACKGROUND (how I got into this mess and what didn’t work):<\/p>\n
My problem started when the battery pack began running out of power much
\nsooner than it “should have”. I tried deep discharging, dropping the battery
\npack from a moderately high distance (and other forms of physical bashing
\nthat some people thought might help), and various other tricks over the
\ncourse of time. At first, these seemed to help slightly, but the
\nimprovements were only temporary.<\/p>\n
Eventually, while using an auto light bulb to discharge the battery pack,
\nI forgot the advice to not go below 1 Volt and let the pack discharge
\ncompletely. After trying to recharge it, I could get the green light to come
\non, but the system would INSTANTLY shut down if the wall-plug power unit was
\nunplugged. A Voltmeter showed that the battery was only putting out 4.8V.
\n(NOTE: the green light doesn’t mean the battery pack is fully charged — it
\nmeans the battery pack isn’t likely to accept any more charge, and that only
\nmeans “fully charged” if all the cells are working.)<\/p>\n
Continued attempts to revive the battery pack eventually left me with a
\nbattery pack in which all cells were “dead” (in “cell reversal” mode, I
\nthink, but I don’t understand NiCads well enough to be sure) — 0V, 0 Ohms
\nresistance, immune to all the simple attempts I tried to charge it.<\/p>\n
WHAT DID WORK:<\/p>\n
Someone on this newsgroup suggested using a large electrolytic capacitor
\ncharged to 8V and discharged through a completely discharged battery pack. I
\ndidn’t have a big enough electrolytic capacitor to do the job, so I tried two
\nalternatives: (1) another battery pack, and (2) an industrial power supply
\ncapable of supplying 10 Volts at 10 Amps.<\/p>\n
Partial success was obtained by connecting a working, fully charged
\nbattery pack’s + to the now-completely-dead battery pack’s +, and – to -,
\nwith just wires, for a few seconds. This produces a modestly bright spark.
\nUsing a second battery pack was good enough to revive 4 of the 6 NiCad cells
\nin the pack, but wasn’t enough to bring back the last two. It might have
\nbeen enough if I’d put some regular batteries in series (and in parallel) to
\nget the voltage and current capacity up a bit.<\/p>\n
The first industrial power supply I tried could only provide up to 5A at
\nup to 10V. This wasn’t enough.<\/p>\n
The second power supply I tried could supply 10A at up to 20V, and 10A at
\njust 10-12V was enough. The power supply was a high grade unit with
\nadjustable current and voltage limits. I connected + to +, – to -, and let
\n10A at 12V flow through the battery for a few seconds. That brought the
\nbattery pack back up to a full 7.2V! The rest of the charging I did on the
\nT1000SE, because I think feeding 120W into a few NiCad batteries for more
\nthan a few seconds at a time is unwise. \ud83d\ude42<\/p>\n
DISCLAIMER:
\n This message provides history and opinions, not advice. If you elect to
\n try to duplicate this success, you do so at your own risk. I did find
\n that a Voltmeter for measuring the battery pack voltage (which was always
\n N * 1.2V) was indispensible.<\/p>\n
COMMENTS ON OTHER SOLUTIONS (given what worked for me):
\n* The big electrolytic capacitor method probably would work, though it might
\n take several “zaps”.
\n* Using a 12V car battery probably also works, but is overkill and looks to
\n be much more dangerous since the current isn’t limited and it probably
\n causes sparks. (The bench supply I used caused no sparks when I touched
\n the probes to the battery pack, even though it instantly went between 0A
\n and 10A output.)
\n* Connecting up a set of 7 1.5V dry cells (or 9 1.2V NiCad cells) in series
\n to get 10+V, probably with N >= 2 sets in parallel to get sufficient
\n amperage, should also be able to do the job. I don’t know of anyone
\n that’s tried this, though.
\n -WBE<\/p>\n
From uwm.edu!cs.utexas.edu!uunet!mcsun!sun4nl!echelon!kees Wed Dec 16 14:55:59 CST 1992
\nArticle: 8465 of comp.sys.laptops
\nNewsgroups: comp.sys.laptops
\nPath: uwm.edu!cs.utexas.edu!uunet!mcsun!sun4nl!echelon!kees
\nFrom: kees@echelon.uucp (Kees Hendrikse)
\nSubject: Re: Very dead T1000SE battery revived
\nOrganization: Echelon Consultancy, Enschede, The Netherlands
\nDate: Wed, 16 Dec 1992 13:44:06 GMT
\nMessage-ID:
\nReferences:
\nLines: 22<\/p>\n
In wbe@bbn.com (Winston Edmond) writes:<\/p>\n
> Thanks to suggestions from this newsgroup, and after some experimenting, I
\n> seem to have managed to revive a completely dead T1000SE battery pack. <\/p>\n
After writing how he did manage to revive the NiCad, Winston Edmond suggest
\nother ways to do it, including:<\/p>\n
> * Using a 12V car battery probably also works, but is overkill and looks to
\n> be much more dangerous since the current isn’t limited and it probably
\n> causes sparks. <\/p>\n
Never ever try this suggestion, as a car battery (especially a healthy one)
\nis capable of delivering 70-80 Amps through the NiCad, which might cause
\nthe NiCad to explode. Always use a device with controlled current. If you
\ncan’t revive the NiCad with about 10 Amps, throw it away, it’s really dead.<\/p>\n
—
\nKees Hendrikse | email: kees@echelon.uucp
\n |
\nECHELON consultancy and software development | phone: +31 (0)53 836 585
\nPO Box 545, 7500AM Enschede, The Netherlands | fax: +31 (0)53 337 415<\/p>\n
From uwm.edu!zaphod.mps.ohio-state.edu!uunet.ca!synapse!peter.latocki Fri Dec 25 17:33:02 CST 1992
\nArticle: 8578 of comp.sys.laptops
\nPath: uwm.edu!zaphod.mps.ohio-state.edu!uunet.ca!synapse!peter.latocki
\nFrom: peter.latocki@synapse.org (Peter Latocki)
\nNewsgroups: comp.sys.laptops
\nSubject: Battert for Old T1000
\nMessage-ID:
\nDate: 25 Dec 92 08:53:00 GMT
\nDistribution: world
\nOrganization: SYNAPSE BBS – GATINEAU, QUEBEC – 819-561-4321
\nReply-To: peter.latocki@synapse.org (Peter Latocki)
\nLines: 13<\/p>\n
TO:gaston@cpsc.ucalgary.ca
\nFROM:peter.latocki@synapse.org<\/p>\n
I picked up a battery for my T1000 at Battery-Biz, 5530 Corbin Ave.
\nSuite 215 Tarzana California 91356 (818)774-1678 or (800)848-6782 a year
\nand a half ago. It sold for $18 and the people there were very nice to
\ndeal with. Also try contacting Toshibs Canada for memory etc. They were
\nrecently listing the RAM upgrade for the old T1000 for $79 but you have
\nto order through a dealer. Call their Fax line at 1-800-663-0378 to
\nhave a copy of their price list faxed to you.
\n—
\n . SLMR 2.1a . Unable to locate Coffee — Operator Halted!<\/p>\n
From uwm.edu!spool.mu.edu!torn!skule.ecf!drill.me!ie.utoronto.ca!xiao Wed Jan 20 15:38:22 CST 1993
\nArticle: 8834 of comp.sys.laptops
\nNewsgroups: comp.sys.laptops
\nPath: uwm.edu!spool.mu.edu!torn!skule.ecf!drill.me!ie.utoronto.ca!xiao
\nFrom: xiao@ie.utoronto.ca (Yan Xiao)
\nSubject: Another successful story of nursing dead battery
\nMessage-ID:
\nSummary: Open it up, find the bad cell, reverse its polarity, DONE
\nKeywords: plyers, fainted
\nOrganization: University of Toronto, Department of Industrial Engineering
\nDate: Wed, 20 Jan 1993 15:48:07 GMT
\nLines: 23<\/p>\n
Here is my experience of fixing a dead batter.<\/p>\n
Problem: the battery won’t hold any charge, but can be used when AC plug
\n\tis in (so what’s the use of the laptop)<\/p>\n
Hypothesis: The polarity of one of the cells is reversed somehow.<\/p>\n
Treatment one: use a car battery to reverse the bad cell
\n\tpotential side effect: explosion
\nTreatment two: open it up and check for bad cell to see if it can be fixed.
\n\tside effect: breaking the nice outfit<\/p>\n
I chose the second method. It required a little resolution to open
\n\tthe battery case (T1000SE), but not too bad.
\n\tUsing a simple flashlight bulb, I located the
\n\tbad cell. Then I used another 7.2v battery to apply to this
\n\tcell, and verified its working by the flashlight.
\n\tI had to use tape to bound the battery in good solid condition.<\/p>\n
Results: it now can holds about 90min of charge.<\/p>\n
Xiao<\/p>\n
From uwm.edu!spool.mu.edu!sol.ctr.columbia.edu!usenet.ucs.indiana.edu!silver.ucs.indiana.edu!wilkr Thu Jan 21 22:06:51 CST 1993
\nArticle: 8854 of comp.sys.laptops
\nNewsgroups: comp.sys.laptops
\nPath: uwm.edu!spool.mu.edu!sol.ctr.columbia.edu!usenet.ucs.indiana.edu!silver.ucs.indiana.edu!wilkr
\nFrom: wilkr@silver.ucs.indiana.edu (richard wilk)
\nSubject: Ideas & Help needed: Running Laptop from Car Battery
\nMessage-ID:
\nSummary: How can this be done???
\nSender: Richard Wilk (wilkr@iubacs, wilkr@ucs.indiana.edu)
\nNntp-Posting-Host: silver.ucs.indiana.edu
\nOrganization: Indiana University
\nDate: Thu, 21 Jan 1993 19:45:28 GMT
\nLines: 53<\/p>\n
I need some feedback, advice and tech help on the following problem.<\/p>\n
I will be spending the summer living in a tent in Central America,
\nmiles from the nearest power line. I will be spending most of my time
\nwriting on my no-name clone 386SX laptop. This uses a fairly standard
\n12V nicad battery, and generally gives me about 1.25 hours.<\/p>\n
I have located a couple of photo-volataic trickle-chargers which will
\ntake about 8 hours to charge my battery (the cheapest one I have found
\nis from a company in Ann Arbor, at 313 453-6746 if you are interested).
\nBut this will only give me an hour of writing a day.<\/p>\n
We have the money to buy a 4000 watt coleman generator (best price
\nso far about $425), but not enough money to run it more than 2-3
\nhours a night (and who wants the noise anyway). We may have enough also
\nfor a small PV array, but I don’t know how large or what wattage.<\/p>\n
I am presently thinking about buying a car battery down there,
\na battery charger, and an inverter. Then I would charge the car battery
\nevery night, and run the computer off it through the inverter the
\nnext day. Damark has a 100 watt inverter for sale right now for
\nc. $70.<\/p>\n
Questions: Will this work? Has anyone tried something similar? <\/p>\n
Sub-questions: How long do I have to run the generator to get the
\nbattery charged?<\/p>\n
How big a PV array would I need to replace the generator completely? (we
\nwill be running a few lights and radios in the evenings too)<\/p>\n
How many hours of use can I expect to get out of a car battery if
\nthe computer is drawing about 45 watts (I *think* that is what
\nthe manual says).<\/p>\n
Does it make any sense at all to be going from 110 volts AC (battery
\ncharger) to 12 Volts DC (battery) to 110 volts AC (inverter, computer
\npower supply) to 12 Volts DC (computer power jack)????? Is there
\nany way to feed the computer, safely, straight from the car battery??<\/p>\n
I would appreciate hearing from anyone with experience, ideas or
\nknowledge (there must be someone with all three). <\/p>\n
Thanks very much<\/p>\n
Rick Wilk<\/p>\n
—
\nRichard Wilk Anthropology Dept.
\nwilkr@iubacs Indiana University
\nvoice 812-855-8162 Bloomington, IN 47405
\n“Things are more like they are now than they’ve ever been before.”<\/p>\n
From uwm.edu!cs.utexas.edu!sun-barr!olivea!sgigate!sgiblab!pacbell.com!att-out!cbnewsh!colin Fri Jan 22 21:27:51 CST 1993
\nArticle: 4811 of comp.sys.palmtops
\nPath: uwm.edu!cs.utexas.edu!sun-barr!olivea!sgigate!sgiblab!pacbell.com!att-out!cbnewsh!colin
\nFrom: colin@cbnewsh.cb.att.com (colin.alan.warwick)
\nNewsgroups: comp.sys.palmtops,sci.physics
\nSubject: Nickel metal hydride cells in standard form factors
\nMessage-ID:
\nDate: 22 Jan 93 19:53:01 GMT
\nFollowup-To: poster
\nDistribution: usa
\nOrganization: AT&T Bell Laboratories – Holmdel NJ
\nLines: 25
\nXref: uwm.edu comp.sys.palmtops:4811 sci.physics:46685<\/p>\n
Does anyone have data on nickel metal hydride rechargable cells in
\nstandard form factors?<\/p>\n
I’d like to populate a table like:<\/p>\n
Form\tCharge\tPrice
\nfactor\t(mA hr)\t($)
\n======================
\nAAA\t???\t???
\nAA\t???\t???
\nC\t???\t???
\nD\t???\t???<\/p>\n
[What ever happened to A and B cells?]<\/p>\n
Also, what is the voltage of a fully charged NiMH cell, under a moderate load?<\/p>\n
Thanx,<\/p>\n
colin.alan.warwick@att.com<\/p>\n
“This is a talk on experimental mathematics, and if that sounds like a
\ncontradiction, it is no more so than `theoretical physics’.”
\n — F. N. H. Robinson.<\/p>\n
From uwm.edu!spool.mu.edu!yale.edu!newsserver.jvnc.net!darwin.sura.net!ukma!cs.widener.edu!iggy.GW.Vitalink.COM!nocsun.NOC.Vitalink.COM!indetech!cirrus!pete Tue Feb 9 11:47:44 CST 1993
\nArticle: 5050 of comp.sys.palmtops
\nNewsgroups: comp.sys.palmtops
\nPath: uwm.edu!spool.mu.edu!yale.edu!newsserver.jvnc.net!darwin.sura.net!ukma!cs.widener.edu!iggy.GW.Vitalink.COM!nocsun.NOC.Vitalink.COM!indetech!cirrus!pete
\nFrom: pete@cirrus.com (Pete Carpenter)
\nSubject: Nickel Hydride Sources
\nMessage-ID:
\nSender: news@cirrus.com
\nOrganization: Cirrus Logic Inc. Fremont, California
\nDate: Mon, 8 Feb 1993 22:41:31 GMT
\nLines: 50<\/p>\n
These two companies sell Nickel Hydride batteries. Both sell AA and C sizes,
\nand both cost exactly the same (Hmmmm) They call themselves “Alternative
\nEnergy” suppliers, which means they sell solar (photovoltaic or PV) panels,
\nand other stuff like 12 VDC to 120 VAC inverters, etc. I’ve bought lots of
\nstuff from both.<\/p>\n
——————————————————————————<\/p>\n
SUNELCO
\n100 Skeets St.
\nP.O. Box 1499
\nHamilton, MT 59840-1499
\norder 800-338-6844
\ninfo 406-363-6924
\nfax 406-363-6046<\/p>\n
catalog\t\tsize amp-hr\tprice
\n————————————-
\nNI-AAHY\t\tAA 1.0 AH\t$ 8
\nNI-CHY\t\tC 3.5 AH\t$16<\/p>\n
——————————————————————————<\/p>\n
Real Goods likes to wear their politics on their sleave, so to speak. If you
\nthink Clinton may ruin the world by being too _conservative_, you’ll fit right
\nin \ud83d\ude42 I like their merchandise, not their preaching. <\/p>\n
Real Goods
\n966 Mazzoni St.
\nUkiah, CA 95482-3471
\n800-762-7325<\/p>\n
50-105\t\tAA 1.1 AH\t$ 8
\n50-104\t\tC 3.5 AH\t$16<\/p>\n
catalog includes this statement –
\n“a little fatter than AA batteries, may not fit in very tight spaces”<\/p>\n
——————————————————————————<\/p>\n
I got some AAs from Real Goods, and they fit in my ZEOS, but unfortunately,
\nI can’t get them to work. Voltage is 1.35, same to Radio Shack AA NiCd.s,
\nwhich work fine.<\/p>\n
—
\nPete Carpenter pete@cirrus.com<\/p>\n
Talk about your plenty, talk about your ills,
\nOne man gathers what another man spills. – Robert Hunter<\/p>\n
From uwm.edu!spool.mu.edu!hri.com!noc.near.net!news.bbn.com!bbn.com!sher Wed Feb 24 13:53:02 CST 1993
\nArticle: 9312 of comp.sys.laptops
\nPath: uwm.edu!spool.mu.edu!hri.com!noc.near.net!news.bbn.com!bbn.com!sher
\nFrom: sher@bbn.com (Lawrence D. Sher)
\nNewsgroups: comp.sys.laptops
\nSubject: Re: T1000SE battery life
\nMessage-ID:
\nDate: 24 Feb 93 13:18:02 GMT
\nReferences:
\nOrganization: Bolt Beranek and Newman Inc., Cambridge MA
\nLines: 66
\nNNTP-Posting-Host: bbn.com<\/p>\n
In article proett@tailspin.nas.nasa.gov (Tom Proett) writes:
\n>Hi,
\n>
\n>I have a T1000SE which has a problem with the battery. It will only
\n>work when it is plugged in now. If I try to unplug it, it will
\n>shut down right away. I took the battery out and hooked it to a
\n>flashlight bulb to drain it. It lighted the bulb brightly for
\n>just under 6 hours. I charged it again and it still would not work.
\n>
\n>Is there a setting on the computer itself which tells it to not shut
\n>down? It seems that the battery is at least fairly good if it can
\n>light a light for more than 5 hours.
\n>
\n>Thanks.
\n>
\n>–
\n>proett@tailspin.nas.nasa.gov
\n>NASA Ames Research Center<\/p>\n
This seems to be a common problem. I don’t know any definitive answers,
\nbut since I faced the same problem, I had occasion to look into it.<\/p>\n
1. Buy replacement cells, open the pack, and put in the new cells. A
\ngood source for replacement cells (in New England): Gates Energy
\nProducts, Inc. 1 Prestige Drive, Meriden, CT 06450-7105 Tel: (203) 238
\n6912, FAX (203) 238 6887 Voice Mail: (904) 462 8725. Attention: David
\nChilds, sales engineer, Northern Sales Region. He was very helpful for
\nme. The cells to get: GLF-1700A Ultramax NiCad. (The cell size,
\nofficially, is 4\/3A.) Cell cost is around $5.50-6.00 as I recall.<\/p>\n
Opening the pack requires a careful dissection along the ultrasonically
\nwelded perimeter seam, visible with the pack upside down. You can put
\nit back together again with glue of various flavors. Be sure to put
\nback the temperature sensor that is nestled in between two of the cells.<\/p>\n
2. Exhume the existing cell(s). Once the pack was open, I found one
\ncell that was weak (discharged quickly) and one that was zero volts,
\nzero ohms. (Even so, of course, the remaining cells would easily run
\nmost flashlight bulbs.) Taking a cue from various other posters (“put a
\ngood cell in parallel with the bad one”, “discharge a capacitor into the
\nbad cell”) and feeling I had little to lose, I decided that if a little
\nwas good, more would be better. So I connected a 12v automobile battery
\ncharger across each bad cell (one at a time). I set the current level
\nto “trickle”, connected positive-to-positive, negative-to-negative, and
\nturned on the power for about 3 seconds. Scarey! Longer connections
\nobvious raise the ante, like inadvertent explosions. An ammeter (on the
\ncharger) showed currents exceeding 10 amperes, tending to decay over a
\nfew seconds to less than 10 amperes, but I wasn’t about to get too
\nacademic about this. A voltmeter showed 0 volts before the treatment
\nand 1.2+ after. I repeated this treatment about 3 times, with a
\nrespectful interval in between, like a minute. Voila, the cell now
\nlooked normal, with an open circuit voltage of about 1.3. I put
\neverything back together, let the Toshiba charger care for the pack
\novernight, and the next morning, it all seemed to run fine.<\/p>\n
Note: I first tried this treatment across several cells in series, only
\none of which was bad. It did not help!<\/p>\n
I can hardly guarantee the safety or long-term consequences of this
\nprocedure. But, clearly, there is some rationale to the talk that
\na sufficient goosing of these cells can exhume them.
\n .—————————————————————-
\n \/Internet email: sher@bbn.com
\nLarry Sher < US Mail: BBN, MS 6\/5A, 10 Moulton St., Cambridge, MA 02138
\n Telephone: (617) 873 3426 FAX: (617) 873 3776
\n\t `—————————————————————-<\/p>\n
From uwm.edu!cs.utexas.edu!uunet!ehbbs!joe.george Sun Mar 7 15:29:10 CST 1993
\nArticle: 5584 of comp.sys.palmtops
\nPath: uwm.edu!cs.utexas.edu!uunet!ehbbs!joe.george
\nFrom: joe.george@ehbbs.com (Joe George)
\nNewsgroups: comp.sys.palmtops
\nSubject: HP95LX batteries ?
\nMessage-ID:
\nDate: 5 Mar 93 23:01:00 GMT
\nDistribution: world
\nOrganization: Ed Hopper’s BBS – Berkeley Lake, GA – 404-446-9462
\nReply-To: joe.george@ehbbs.com (Joe George)
\nLines: 26<\/p>\n
SDFW-> What does the ’95LX use for batteries ?<\/p>\n
Just about any AA batteries work, with varying results. The HP’s
\ninternal battery-level meter is geared to the steady voltage dropoff of
\nalkaline batteries; the reason NiCd batteries stink out loud in
\nequipment like this is that when NiCds run out of gas, the voltage drop
\noff is quick and very steep and _very_ unforgiving. I’ve not used NiMH
\nbatteries in my HP (but I have one in my laptop, it’s got a lot longer
\nlife but an odd voltage drop off. Not bad, just odd.)<\/p>\n
The batteries I now exclusively use in my HP are Eveready Energizer
\nHigh-Energy Lithium AA Batteries. Theyre about $1.50 a pair more
\nexpensive than standard Energizers but I get 2-3x the life out of them.
\nThey, too, have a kind of quick drop off (I ran for 3 weeks with the
\nbattery meter on “Full” and went down to “Empty” in a matter of 2 days)<\/p>\n
Joe<\/p>\n
* SLMR 2.1a * TV is a medium; anything well done is rare.<\/p>\n
—-
\n+—————————————————————————+
\n| Ed Hopper’s BBS – ehbbs.com – Berkeley Lake (Atlanta), Georgia |
\n|USR\/HST:404-446-9462 V.32bis:404-446-9465-Home of uuPCB Usenet for PC Board|
\n+—————————————————————————+<\/p>\n
From uwm.edu!wupost!howland.reston.ans.net!gatech!news.ans.net!cmcl2!netnews!jan.ultra.nyu.edu!edler Wed Apr 21 15:28:17 CDT 1993
\nArticle: 10220 of comp.sys.laptops
\nPath: uwm.edu!wupost!howland.reston.ans.net!gatech!news.ans.net!cmcl2!netnews!jan.ultra.nyu.edu!edler
\nFrom: edler@jan.ultra.nyu.edu (Jan Edler)
\nNewsgroups: comp.sys.laptops
\nSubject: Re: Getting rid of Nicad memory effect
\nDate: 19 Apr 1993 17:57:14 GMT
\nOrganization: New York University, Ultracomputer project
\nLines: 27
\nMessage-ID:
\nReferences:
\nNNTP-Posting-Host: jan.ultra.nyu.edu<\/p>\n
In article jarnold@tixel.mv.com writes:
\n>I had posted a note a few weeks ago about how to “fully discharge” a
\n>nicad battery pack (that powers my notebook pc) that has apparently
\n>developed the dreaded nicad memory effect. Brand new, I used to be
\n>able to get 3+ hours of heads-down work out of a charge, but now
\n>(same apps, same work habits) I’m lucky to get as much as *one* hour.<\/p>\n
I have been using a resistor to regularly discharge my T1000SE battery
\nfor several years. This is a 7.2V pack. I use a 10 Ohm power resistor
\nfrom Radio Shack. I remove the battery, place it upside down, place
\nthe resistor on the battery contacts (I’ve bent the resistor’s leads to
\nmake this convenient), and put a little weight on it to make a good
\nconnection. I normally connect a voltmeter to it, and wait about 10 or
\n12 minutes for the voltage to drop below 6V. I keep the voltmeter on
\nmy desk, so this is convenient, but otherwise I just time it for about
\n10 minutes. I use a kitchen timer to remind me when to check the
\nbattery. I go through this procedure almost every time the machine
\nshuts off, before recharging (i.e., about daily). This arrangement
\nseems to work well.<\/p>\n
When I started doing this, a few years ago, I drained the battery all
\nthe way (until the resistor was cold). I never had any trouble, but
\nvarious people were making arguments that this could damage the cells,
\nso now I stop somewhere below 6V. So far so good.<\/p>\n
Jan Edler
\nedler@nyu.edu<\/p>\n
From uwm.edu!cs.utexas.edu!uunet!olivea!charnel!csusac!sactoh0!mnj Tue May 18 14:40:39 CDT 1993
\nArticle: 14012 of comp.sys.handhelds
\nNewsgroups: comp.sys.handhelds
\nPath: uwm.edu!cs.utexas.edu!uunet!olivea!charnel!csusac!sactoh0!mnj
\nFrom: mnj@sactoh0.sac.ca.us (Mark Newton-John)
\nSubject: Re: Batteries for the Psion Series 3
\nMessage-ID:
\nOrganization: Sacramento Public Access Unix
\nReferences:
\nDate: Tue, 18 May 93 08:38:59 GMT
\nLines: 29<\/p>\n
In ah57@unix.brighton.ac.uk (Andrew) writes:<\/p>\n
>Has anybody found it possible to use rechargeable batteries in their
\n>Psion Series3? I Have tried using rechargeables but they seem only to last
\n>for about a day before I get lots of Main battery is low warnings.<\/p>\n
The problem with rechargeables is that they are not the 1.5 volts
\nthat regular alkalines give. (typically 1.2 volts)<\/p>\n
The Psion sees the low voltage and will give the low battery
\nwarning, and if ignored, will start to use the memory battery.<\/p>\n
With the Portfolio, what can happen is that the low battery warning
\ncould be missed, and when the power falls off (rechargebles fall
\noff rapidly) memory loss will occur.<\/p>\n
The best batteries that I have found to use in handhelds are Maxell
\n(yes, the tape company) Photo AA (LR6) alkalines. They are a more
\npowerfull alkaline, designed for high drain useage in camera
\nflashes and motor drives. They are $3.49 per 4-pack. They have
\noutlasted a set of Energizers (stupid rabbit) and Duracells.<\/p>\n
—
\nmfolivo@sactoh0.SAC.CA.US SAC-UNIX (916) 649-0161
\nThe Good Guys!\t\tWe know our stuff
\nAudi\t\t\tThe Alternate Route
\nAtari\t\t\tPower without the Price<\/p>\n
\ufffd<\/p>\n
