To fix this problem, I made a timed duplex power outlet. I plug the timed outlet into a 120v outlet. Then, plug the battery charger into the duplex outlet attached to the timer. Finally, I set the timer to 20 minutes and walk away.
The parts list to make this is simple:
- One (1) double gang electrical box.
- One (1) GE 15305 In Wall Spring Wound 60 Minute Countdown Timer
- One (1) duplex outlet
- One (1) old power cable from a computer
- Extra electrical wires (black / white / green)
Making this is also simple.
Step 1: Assemble the Parts
Assemble the parts as follows. (Sorry for not having any pictures but its pretty straightforward.)
Step 1: Cut the extra electrical wires into 8-12 inch lengths. Strip 1/8" off of each end.
Step 2: Cut off the female end of the computer power cable and strip off 6-8 inches of the outside case. Then, strip 1/8" off the end of each conductor.
Step 3: Remove one of the knockouts in the back of the double gang electrical box and insert the cut end of the computer power cable into the box.
Step 4: Attach the black conductor from the power cable to the line connector on the timer switch. Attach the white and green conductors from the power cable to the appropriate connections on the duplex outlet.
Step 5: If the timer switch did not come with a conductor for the load, use the extra black wire from step one. Connect the black wire from the load connector on the timer switch to the positive power connector (gold or yellow) on the duplex outlet.
Step 6: Attach the timer switch and duplex outlet to the electrical box using the mounting screws that came with each device.
Step 7: Test with a nightlight and/or electrical tester.
Step 2: Print a Custom Faceplate
One problem I had is that the faceplate that came with the timer was too wide. It covered the timer and a bit of the duplex outlet. I found a Thing on Thingiverse that uses the Customizer to custom build faceplates that cover from one to five outlets with any configuration. I used it to make a custom faceplate for two outlets with a single hole for the timer on the left-hand side and holes for a duplex outlet on the right-hand side. I printed it on the Makerbot 3D printer at the Milwaukee Makerspace using black PLA filament. I used 100% infill to make it solid and durable.
One problem I had with the print was that the raft stuck to the surface in some spots and would not come off. So, there are a few rough looking spots. Another problem is that the hole for the timer knob was a bit too small. I had to drill it out slightly bigger.
After attaching the new faceplate, I used my label maker to print the numbers for the dial.