Ni-Cad batteries for TI 58c calculator
Conrad Jacoby
Howdy!
I just rescued a TI 58c calculator fromthe local thrift shop, and, after
finding the AC adaptor (this particular place as the odd practice of
taking all AC adaptors that come in and pricing them separately from the
items that they were intended to power--I had to buy the calculator and
adaptor as separate items), took it home.
The Nicad battery pack is, predictably, corroded, but I'd like to replace
the three cells. Can anyone tell me what kind of replacement battery I
should look for? The three cells are look like AA batteries, but I know
better than to assume that an old calculator, much less one driving an LED
display, is likely to work on 4.5 volts DC.
Thanks in advance!
--Conrad J.
Jac...@his.com
--
Conrad J. Jacoby
2701 South 11th Street
Arlington, VA 22204
Kenneth Brody
Conrad Jacoby (Jac...@his.com) wrote:
[... just got an old TI-58c ...]
: The Nicad battery pack is, predictably, corroded, but I'd like to replace
: the three cells. Can anyone tell me what kind of replacement battery I
: should look for? The three cells are look like AA batteries, but I know
: better than to assume that an old calculator, much less one driving an LED
: display, is likely to work on 4.5 volts DC.
Don't discount the possibility. My first calculator was a TI-1500. (LED
display, 8 digits, 4-function.) It ran on 3 AA regular batteries, or 4
rechargables. I remember those battery packs from a later calculator (I
think it was a TI-52?) and they certainly looked like your run-of-the-mill
AA batteries, but I never took one apart to see.
--
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| Kenneth | kenb...@cloud9.net | "The opinions expressed herein |
| J. | | are not necessarily those of |
| Brody | http://www.cloud9.net/~kenbrody/ | AdminaStar Communications." |
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Tim Shoppa
In article <Jacoby-0210...@205.177.25.99>,
Conrad Jacoby <Jac...@his.com> wrote:
>Howdy!
>
>I just rescued a TI 58c calculator fromthe local thrift shop, and, after
>finding the AC adaptor (this particular place as the odd practice of
>taking all AC adaptors that come in and pricing them separately from the
>items that they were intended to power--I had to buy the calculator and
>adaptor as separate items), took it home.
>
>the three cells. Can anyone tell me what kind of replacement battery I
>should look for? The three cells are look like AA batteries, but I know
>better than to assume that an old calculator, much less one driving an LED
>display, is likely to work on 4.5 volts DC.
The calculator itself doesn't work on 4.5 volts DC - but the battery
voltage from 3 Ni-Cad cells (about 3.6 to 4.2 volts) is probably stepped
up by a voltage converter before going into the calculator. There's
almost certainly a small PC board in the battery pack which does this
for you.
If the TI 58c pack is identical to the TI 30 pack, all you need are
3 AA cells. In the phone section of many discount stores these days
you'll be able to find such packs with solder tabs and attached wires.
They also probably have 2/3 height cells as well, if
that's what you need.
Tim. (sho...@triumf.ca)
Peter Kerr
Jac...@his.com (Conrad Jacoby) wrote:
> The three cells are look like AA batteries, but I know
> better than to assume that an old calculator, much less one driving an LED
> display, is likely to work on 4.5 volts DC.
>
Umm, I see three possibilities here:
a) you're being modest about your ignorance, or
b) you're being obstinate in refusing to believe the obvious, or
c) that thrift shop sells the labels off the bottom of the
calculator & psu as separate items too...
--
Peter Kerr bodger
School of Music chandler
University of Auckland NZ neo-Luddite
gl...@glass.cv.lexington.ibm.com
In <Jacoby-0210...@205.177.25.99>, Jac...@his.com (Conrad Jacoby) writes:
>Howdy!
>
>I just rescued a TI 58c calculator fromthe local thrift shop, and, after
>finding the AC adaptor (this particular place as the odd practice of
>taking all AC adaptors that come in and pricing them separately from the
>items that they were intended to power--I had to buy the calculator and
>adaptor as separate items), took it home.
>
>The Nicad battery pack is, predictably, corroded, but I'd like to replace
>the three cells. Can anyone tell me what kind of replacement battery I
>better than to assume that an old calculator, much less one driving an LED
>display, is likely to work on 4.5 volts DC.
>
>
>--Conrad J.
> Jac...@his.com
>
>--
>Conrad J. Jacoby
>2701 South 11th Street
>Arlington, VA 22204
It very probably did work off of either 4.5 or 3.75 (3x1.25 volt nicads).
LEDs only require about 2 volts to illuminate, so even 3.75 volts gives
plenty of margin. I know some of the HPs (25?) worked off of a pair of
nicads for about 2.5-3.0 volts, since I've done said battery-ectomys on
them.
Dave
Conrad Jacoby
In article <p.kerr-0310...@news.auckland.ac.nz>,
p.k...@auckland.ac.nz (Peter Kerr) wrote:
> Jac...@his.com (Conrad Jacoby) wrote:
> > The three cells are look like AA batteries, but I know
> > better than to assume that an old calculator, much less one driving an LED
> > display, is likely to work on 4.5 volts DC.
> Umm, I see three possibilities here:
>
> a) you're being modest about your ignorance,
Harumph.
>
> b) you're being obstinate in refusing to believe the obvious,
I've been putting 3.6 volt lithium backup cells in a variety of pinball
machines for a while. Looks just like an AA cell until you read the fine
print. The nicads in the TI battery back have no identifying marks, other
than a very helpful, "Made in Mexico."
>
> c) that thrift shop sells the labels off the bottom of the
> calculator & psu as separate items too...
No labels on either. It is as if someone scrubbed the adaptor clean of
any identifying marks except for the "TI" logo which is stamped into the
plastic (the rest was painted on).
Tim Shoppa
In article <530d60$u...@ausnews.austin.ibm.com>, <wa4...@vnet.ibm.com> wrote:
>It very probably did work off of either 4.5 or 3.75 (3x1.25 volt nicads).
>LEDs only require about 2 volts to illuminate, so even 3.75 volts gives
>plenty of margin. I know some of the HPs (25?) worked off of a pair of
>nicads for about 2.5-3.0 volts, since I've done said battery-ectomys on
>them.
Most early LED calculators that ran off just 2 Ni-Cad cells had a voltage
converter(either in the pack, or in the calculator) that stepped up the voltage
to the region of 6 to 9 VDC. Many of the TI's I've seen that
have 3 cells also had a step-up converter, which you will find when
you disassemble the battery pack. They actually needed 7 to 9 VDC
to run.
Most 4-cell calculators seem to not have such step-ups. I suppose
by the time you're at 4.8 or 6V a couple of diode drops aren't such
a big deal :-). (Tell that to folks designing 3.3V logic!)
Tim.
Tom Watson
In article <Jacoby-0210...@205.177.25.99>, Jac...@his.com (Conrad
Jacoby) wrote:
> Howdy!
>
> I just rescued a TI 58c calculator fromthe local thrift shop, and, after
> finding the AC adaptor (this particular place as the odd practice of
> taking all AC adaptors that come in and pricing them separately from the
> items that they were intended to power--I had to buy the calculator and
> adaptor as separate items), took it home.
>
> The Nicad battery pack is, predictably, corroded, but I'd like to replace
> the three cells. Can anyone tell me what kind of replacement battery I
> should look for? The three cells are look like AA batteries, but I know
> better than to assume that an old calculator, much less one driving an LED
> display, is likely to work on 4.5 volts DC.
>
Go down to the local electronics store (Radio Shack) and look for an
encapsulated (shrink wrap) set of batteries that looks like what you
want. These are usually goodies for portable telephones, and they seem to
need replacing quite often. I needed to do something quite similar to
what you need on an HP-35 (it uses 3 AA NiCad's in a special holder).
What I ended up doing is just wrapping the stripped leads around the
correct contacts in the calculator, adding a piece of foam stuffing to
make sure the thing didn't rattle to death, and called it "good".
Most of the time the battery sets are on blister cards.
Good luck.
--
Tom Watson
t...@3do.com (Home: t...@johana.com)
Charles Richmond
Tom Watson wrote:
>
> In article <Jacoby-0210...@205.177.25.99>, Jac...@his.com (Conrad
> Jacoby) wrote:
>
> > Howdy!
> >
> > I just rescued a TI 58c calculator fromthe local thrift shop, and, after
> > finding the AC adaptor (this particular place as the odd practice of
> > taking all AC adaptors that come in and pricing them separately from the
> > items that they were intended to power--I had to buy the calculator and
> > adaptor as separate items), took it home.
> >
> > The Nicad battery pack is, predictably, corroded, but I'd like to replace
> > the three cells. Can anyone tell me what kind of replacement battery I
> > should look for? The three cells are look like AA batteries, but I know
> > better than to assume that an old calculator, much less one driving an LED
> > display, is likely to work on 4.5 volts DC.
> >
>
>
Yes, you certainly *can* go down to the local electronics store--or even
Walmart--and find these NiCad battery packs that were meant for cordless
phones. And they *probably* would work well, after you recombine the
cells to look like the ones that the TI originally had. ---OR---
You can call 1-800-TI-CARES (that's 1-800-842-2737, to the
alphanumerically challenged) and talk to their replacement parts
department. They can sell you the TI part for your TI calculcator. Of
course, you will pay a little *more* for it and also have to pay
shipping. They also offer repair service for some items, although
"repair" may end up being "replace with a re-built model." (I am *not*
sure if this 800 number works for outside the USA.)
--
+---------------------------------------------------------------------------+
| Charles and Francis Richmond
<rich...@plano.net> |
+---------------------------------------------------------------------------+
vse
In article <530hii$g...@nntp.ucs.ubc.ca>, sho...@alph02.triumf.ca says...
> In article <530d60$u...@ausnews.austin.ibm.com>, <wa4...@vnet.ibm.com> wrote:
> >It very probably did work off of either 4.5 or 3.75 (3x1.25 volt nicads).
> >LEDs only require about 2 volts to illuminate, so even 3.75 volts gives
> >plenty of margin. I know some of the HPs (25?) worked off of a pair of
> >nicads for about 2.5-3.0 volts, since I've done said battery-ectomys on
> >them.
>
> Most early LED calculators that ran off just 2 Ni-Cad cells had a voltage
> converter(either in the pack, or in the calculator) that stepped up the
> voltage to the region of 6 to 9 VDC.
> Many of the TI's I've seen that have 3 cells also had a step-up converter,
> which you will find when you disassemble the battery pack.
say "motherboard"?
> They actually needed 7 to 9 VDC to run.
And, yes, you can simply change the batteries for standard 1.2 V NiCd
cells (I did that on my 59 twice...)
Good Luck, Guido