DIY USB Charging Port for Cordless Drill Battery

If you're interested in DIY balance charging ports, take a look at this article.

If the battery of your cordless drill is no longer working, you can prepare a single battery and use an RC balance charger to recharge it. Additionally, you'll need some USB male and female connectors for the modification.

With the process outlined above and the parts you've purchased, DIY becomes much easier.

First, as shown in the image below, the main focus of the modification is outlined. The image shows the setup before modification:

As you can see, after removing the D-port from the circuit board, there is still ample space. The USB female connector fits perfectly in terms of size. The next step is to use a utility knife and diagonal pliers to trim the excess parts of the USB shell and battery casing. Attach the USB port using hot glue and 502 glue. Finally, solder the four silicone wires in the order of +, -, +, -, as shown. Use heat shrink tubing and apply glue to ensure proper insulation (this is very important to avoid short circuits). Then, cut the wires to the required length based on the battery soldering positions and solder them accordingly. By this point, you've completed about 90% of the work.

Next, carefully check if there are any wiring errors and measure the voltage between the two terminals of the balance connector. Once you're sure everything is correct, you can reassemble the casing. Finally, use a balance discharger to measure and ensure the output is normal.

Completion.