The subject on this page may seem like unnecessary nonsense to people who simply toss good
equipment into the trash when they don't work. If you live on a tight budget you don't have that luxury (and my Social Security retirement dictates a tight budget).

One problem I've encountered over the years that renders a piece of equipment useless is corroded or broken battery contacts in low power, battery operated electronic equipment. I've used several methods to overcome that problem - some worked and some didn't. Now I've found a cure that will work for some hardware and it works so well that I think I should share it.

The Problem: I was given a nice optical mouse for Christmas (thanks, Donnie). I immediately enjoyed the freedom I got with the optical mouse. The mouse uses two AA batteries and it doesn't have a cut-off switch, so the mouse is using a small amount of battery power 24 hours per day. After a few days and in the middle of doing something that I thought was important, the mouse quit. I changed batteries and the mouse began working. In a few more days, the mouse stopped again - and again fresh batteries were needed. I didn't have any more AA batteries on hand so I reverted to using the old PS 2 mouse. I missed the freedom of movement that I got when using the optical mouse but heck, I couldn't continue buying batteries every few days.  

The Solution: I needed an off/on switch so I could save battery power. I found a method that works.


 

The mouse is 'on' 24 hours every day
(see the orange/red light) and no way
to turn it off. It needs a switch.
But where and how to add a switch?
(I have the battery cover removed.)
First, I diagrammed the power circuit. It's a simple series circuit that could be switched off and on by
simply breaking and restoring battery continuity, which could be done by cutting the clip into two pieces.

The rear clip could be cut (where the black line is shown) and a wire could be connected to each 
piece of it and then to a switch.

But I didn't want to use the clip, which is very thin metal. So I devised another way.

A spring keeps enough pressure on the battery to insure good contact. My substitute for the clip must also provide spring pressure on the battery. My idea was to make two small contacts from paper clips  The metal used to make
 paper clips is strong and springy. Making two such contacts will allow you to place one at the battery (-) and one at the battery (+). Power to the mouse is provided when a wired switch is cut on, and power stops when the switch is off.  
The small metal paper clip is the type I used. In my pictures, I'm using a larger, plastic coated paper clip because it shows up better in pictures.
1. Open the paper clip.
2. Cut off the excess.
3. Use needle nose pliers to make a bend.
4. Compress the bend - leave a gap to make it springy.
5. Bend one end across and solder a wire to it.
6. Cut off any excess wire.
7. Make a second contact just like this one.
Press the two new contacts into place in the battery clip slots - contacts must not touch each other.
Solder the wire ends to a small on/off switch.
Snip out a small bit of the plastic case for the wires to exit.
Replace the battery cover.
Place the switch where it's most comfortable. I just let mine hang loose - the wires hold it up.
If you did all this correctly, you now can cut the power off/on to your optical mouse and save
your battery power.
Now that I've found that a small metal paper clip can be made to replace original contacts in
many devices, I have several more to replace and I can think of several innovations. I should
have thought of this years ago.
Doug Dickens,   Oct. 18, 2007.
The original clip.
1.
2.
3.
4.
5.

Public Notice: there are several handyman  do-it-yourself  items on this Web site that require some care when using them or the tools and/or electricity when constructing them. I offer my ideas freely and if you use any of these ideas you are responsible for all aspects of that use. If you attempt to construct and/or use any of these items, you do so at your own risk.  Thank you, Doug Dickens.

Making Battery Contacts from Paper Clips
Switch is OFF.
Switch is ON.
Battery cover is in place.
Switch and wire are no bother to me.
Below are clearer pictures of the paper clip bends thanks to my friend Marshall, who has a better camera. He would allow me to borrow his camera but I can't swim across the Atlantic to get it, ha ha. 
When the clips are bent to fit the battery case and the wire is soldered in place as above, the assembly is ready to install - then solder the switch to the wires. A few drops of cement can be used to hold the clips in place if needed.
aaaaaaaaaaaaiii