My Apple trackpad never leaves my desk. It always stays within few inches in front of my iMac. Therefore, its silly to have it battery powered. I also like to practice what I preach.
It is quite difficult to find an alternative to Apple trackpad in general. Let alone, finding one that is wired (usb powered) and has the aesthetics similar to what Apple offers is nearly impossible. The surface texture and tactile experience of the Apple trackpad is identical to my MacBookPro, and I prefer to keep it that way. So, this is how I transformed my Apple trackpad to be battery-free.
I initially planned to draw AC power from USB. But before you can do that, you need to convert the 5 volts from USB down to 3 volts that Apple trackpad uses (2 AA 1.5v batteries = 3v). That would require some voltage math along with fiddling with resistors. Until I can figure that out, I went ahead and bought a 3V output AC wall adaptor. The result is the same. It will just draw AC power from the wall outlet instead of the USB port.
This is the 3 volt output adaptor
1. Cut the output end plug of the AC adaptor wire (opposite of the wall side)
2. Drill a hole on the back of the trackpad battery barrel
3. Insert cut end of AC adapter wire into the hole and out through the battery cap
4. Find a wooden dowel about 1/4 inch in diameter. Length should roughly equal that of 2AA batteries (maybe little shorter to compensate for the 2 screws at each end)
5. Then I soldered the correct wires to the metal screws (careful not to mix up + and – )
6. Used some electrical tape to wrap the wire and the wooden dowel
7. Insert the finished wooden dowel into the battery compartment, carefully guiding the wire while pulling out the excess wire back from the drilled hole
A. 3V AC adaptor
B. Wooden dowel (about 1/4″ diameter, length of 2 AA batteries – or you can be creative with pencil or empty pen barrel)
C. Solder or wrap wires to metal screws at each end
The result – AC powered Apple Trackpad
Note that the trackpad will still use Bluetooth to communicate data to the computer. The AC power just provides…, well, just power.
I am battery-free forever!
** Disclaimer: If you are considering doing this, attempt at your own risk. This set-up works fantastically for me because I sort of knew what I was doing. Fiddling with electrics and voltage is no child’s play and lot of things (including burning down the house, electric shocks, frying your equipment, etc…) can go wrong depending on how handy, steady, and careful you are.