Craig Younkins' Blog

The battery capacity of my beloved Logitech MX1000 mouse had deteriorated over time. It was lasting only 2-3 days tops before the charge level would turn red, its lowest level. So I decided to find out how I could replace the internal, "non-replaceable" battery.

As it turns out, doing so isn't too bad. There are multiple sites available with instructions. While they are OK instructions, I have a few comments.

I ordered an NP-120 camera battery to replace the one inside the MX1000. Before we put in the new battery, we decided to take apart the old one. Inside the blue casing of the original battery, the three wires are soldered to a small circuit board. It was easy to unsolder the wires, and this allowed us to use the full length of the wire. Having more wire to work with made things a lot easier, because there isn't a lot of room to play with.

It is generally not a good idea to expose batteries to heat, so why would you think to put a very hot soldering iron to it? We came up with a better idea. We cut small strips of brass which we bent into U shapes and soldered the battery wires to the brass plates. Then we put the bent brass plates up against the battery contacts, and held them in place using self-fusing silicon tape. This kind of tape may also be known as "self-vulcanizing tape" although I believe the use of that word is incorrect. The tape isn't sticky at all, but has a layer of plastic which you peel off, allowing the tape to fuse to itself. Before you try to put the battery in the mouse, it is a very good idea to check the contacts by connecting a voltmeter to the socketed end that plugs into the PCB. As usual, red is positive and black is negative.

We ran into more problems when we tried to put the battery back in. It appeared that our tape arrangement had added too much thickness to the battery, and it wouldn't fit very well in the casing. Putting it back together might go well for a bit, but we found it was simply too much when we tried to fit the whole mouse back together. Since we didn't want to change our arrangement of the battery contact, we decided to get rid of the entire battery holder and hot glue the battery to the inside top of the mouse. This ended up working quite well, and the mouse fit together with a snap.

The result is a much better performing MX1000. The battery now lasts a solid 7 days before needing a recharge, and I'm quite happy with that. If I ever need to, I can replace the battery again for $10 and get more life out of a great mouse.

Like hardware hacking? You might try hacking your toner drums to get more life out of them.