Rigging a battery onto a solar calculator

Simmon · Post by **Simmon** » 2006-02-20 05:19pm

I noticed today that the solar power cell on my calculator was cracked. As a result, the calculator in no longer in working condition. As I'll be buying a new one anyway, it can't hurt to mess around with this one. My question is, is it possible to remove the solar cell and rig a battery to act for it, and if so, what battery should I use? The calculator is a CASIO fx-260 solar, an image can be found here.

Enigma · Post by **Enigma** » 2006-02-20 05:27pm

Try a car battery.

Simmon · Post by **Simmon** » 2006-02-20 05:33pm

Let me rephrase. I meant a battery the calculator can run on, not one that will overload it and possibly kill the circuits.

darthdavid · Post by **darthdavid** » 2006-02-20 05:41pm

Simmon wrote:Let me rephrase. I meant a battery the calculator can run on, not one that will overload it and possibly kill the circuits.

Ok, what you've got to do, you've got to get a battery holder, then wire it so it's positive and negative ends are wired same as the solar cells were. To figure out the battery just get the output specs for the solar cell on that calculator and use a battery type that has the same specs.

GrandMasterTerwynn · Post by **GrandMasterTerwynn** » 2006-02-20 05:56pm

Simmon wrote:Let me rephrase. I meant a battery the calculator can run on, not one that will overload it and possibly kill the circuits.

Those little hand-held calculators typically run on one or two coin-shaped batteries providing between 1.5 VDC to 3.0 VDC at around 80 mAh. In some rare cases, you'll find dinky calculators running on larger button-cell batteries providing between 3.0 VDC and 6.0 VDC. However, your Casio isn't likely to require that much voltage. More likely than not, it will be a standard 1.5 VDC to 3.0 VDC (with the former being the first you should try, and the latter the one you should try should it not power up at 1.5 VDC)

Simmon · Post by **Simmon** » 2006-02-20 05:57pm

I tried a AA battery. It works!

Now I need to duct tape it in place

Somehow, I like messing with electronics.

EDIT: GAH! This calculator was soley on solar power which means that it does not turn off! No off button! It turned off when it lost solar power! Now I have to rig a switch to have and on/off ability. I think a removable wire with duct tape will do. Just rip it off to turn it off, stick back on to turn on.

I go to a Science/Technology program at school, my friends will love this!

Also, if could find one, I'll use a real switch.

Post by **Sea Skimmer** » 2006-02-20 06:28pm

Simmon wrote:Let me rephrase. I meant a battery the calculator can run on, not one that will overload it and possibly kill the circuits.

There would be no ‘possibly’ about it.

Simmon · Post by **Simmon** » 2006-02-20 06:38pm

I realize that. I went for sarcasm as well as Enigma.

Simmon · Post by **Simmon** » 2006-02-20 07:04pm

Update: The battery is secured with scotch tape, and I even managed to make a power switch of sorts. I have a small piece of metal bent into an L near my battery, and I push it against the battery when I want power. It's unstable, but it works!

I'll post an image of "my calculator now" soon.

Edit:
Images can now be found here, here,here and here.

FSTargetDrone · Post by **FSTargetDrone** » 2006-02-20 08:13pm

Simmon wrote:Update: The battery is secured with scotch tape, and I even managed to make a power switch of sorts. I have a small piece of metal bent into an L near my battery, and I push it against the battery when I want power. It's unstable, but it works! I'll post an image of "my calculator now" soon.

Well that looks crappy. Come on now! You need to take this seriously. First, rig up some sort of battery holder. Failing that, buy one from Radio Shack. Then you need to construct a housing to cover the case and wires on the bottom. Of course, you'll need a method to secure the cover to the bottom. Perhaps a system of hinges and a simple lock. Make sure they are constructed of brass. Very important. Gotta make it look flashy. But no iron. Far too heavy.

Rivet the hinges to the side and perhaps apply some felt to the bottom for that smooth finish.

Edit, I would also reroute the wires coming out of the solar cell opening through the bottom and cover the opening with some sort of engraved nameplate.

Simmon · Post by **Simmon** » 2006-02-20 08:16pm

Valid points, but it's not like I'm keeping it for use.

FSTargetDrone · Post by **FSTargetDrone** » 2006-02-20 08:19pm

Simmon wrote:Valid points, but it's not like I'm keeping it for use.

Nonsense. You should plan on investing heavily into this project. I'm thinking custom paint job or, if you're into a custom G-Shock look, perhaps some rubberized protective covering. And think about angling the base for easy viewing. That strip of metal on the bottom just isn't cutting it.

Simmon · Post by **Simmon** » 2006-02-20 09:18pm

You know, you might have me convinced. This thing is dead anyway, so I might as well mess with it some more. I could pull alot of stuff in tech class, as many tools and materials are availible. It will be much more interesting then the stuff we do now...
I could possibly *make* a battery holder. Don't know about the paint, but a protective cover is possible.

SCRawl · Post by **SCRawl** » 2006-02-20 09:27pm

Why not buy a little solar cell? It'll take up less space....

FSTargetDrone · Post by **FSTargetDrone** » 2006-02-20 09:42pm

Simmon wrote:You know, you might have me convinced. This thing is dead anyway, so I might as well mess with it some more. I could pull alot of stuff in tech class, as many tools and materials are availible. It will be much more interesting then the stuff we do now...
I could possibly *make* a battery holder. Don't know about the paint, but a protective cover is possible.

There you go! Get creative. Jazz that sucker up and come back and show us what you made of it.

SCRawl wrote:Why not buy a little solar cell? It'll take up less space....

Well that's no fun!

(Edit: consolidated posts)

Sonnenburg · Post by **Sonnenburg** » 2006-02-20 09:47pm

Simmon wrote:I tried a AA battery. It works! Now I need to duct tape it in place
Somehow, I like messing with electronics.

EDIT: GAH! This calculator was soley on solar power which means that it does not turn off! No off button! It turned off when it lost solar power! Now I have to rig a switch to have and on/off ability. I think a removable wire with duct tape will do. Just rip it off to turn it off, stick back on to turn on. I go to a Science/Technology program at school, my friends will love this!

Also, if could find one, I'll use a real switch.

Memories... I did the same thing when my solar calculator broke in the eighties, and yeah, a AA battery works just fine. What I did (because I loved low tech things) was used electrical tape to secure the wires on the calculator, then taped one to an end to the battery. The other end had two tabs off of soda cans, one taped to the wire, the other to the battery, and they would hook together to complete the circuit. Like I said, it was the eighties and MacGyver was still big at the time.

Simmon · Post by **Simmon** » 2006-02-20 10:00pm

MacGyver was all I was thinking.
It might be some time untill I complete this thing. I can't believe I'll actualy do it.

Elheru Aran · Post by **Elheru Aran** » 2006-02-20 11:19pm

Here's a tip to start off with... ditch the Scotch tape. No offense, but looks like it was put together by a third grader. Admittedly, a smart third grader with an Erector set, but still...

Simmon · Post by **Simmon** » 2006-02-21 07:44am

How very true...The metal didn't come from an Erector set, but off a Junior Electricity Lab (not much different)
Which reminds me...unless I'm mistaken, I have a battery holder in my Erector set...

FSTargetDrone · Post by **FSTargetDrone** » 2006-02-21 11:55am

Simmon wrote:How very true...The metal didn't come from an Erector set, but off a Junior Electricity Lab (not much different)
Which reminds me...unless I'm mistaken, I have a battery holder in my Erector set...

Ah-ha!

You know, all kidding aside, you could stick that battery holder horizontally across the back/top of the calculator, opposite where the solar cell was. That way you can have the thing angled upwards a bit, making the battery holder act as a stand.