Project:DeWalt Battery Replacement
| ProjectInfoBox DeWalt Battery Replacement (NiMH to LiPo) | |
|---|---|
| |
| Status: | done |
| Release Date: | October 2018 |
| Initiator: | |
| Team: | Johannes |
| Materials Used: | DeWalt cordless drill with broken battery, 3S lipo, a balancer board |
| Tools Used: | soldering iron, 3D printer |
| Software Used: | Fusion 360 |
| Approx. Cost: | approx. 10 € (without the battery) |
A DeWalt_DC740KA Cordless Drill that we used to have had a broken battery which needed to be replaced. In order to replace it, we used LiPo batteries with a custom charging curcuit. In addition to this page, the discussions during the replacement can be read on github.
Battery Circuit
connections between Battery and Protection Circuit:
Originally, the battery circuit was using a 20A protection circuit:
This was modified in order to support 30A:
The battery case had to be recreated. This was done using the 3D Printer. The files can be found here.
Charging Station
Since the battery got replaced, we also needed a new charging station:
The charging station is nothing special, just a DC to DC converter with constant current and constant voltage (CC/CV). The current is set to 0.5A and the voltage to 12.5V which provides a safe charging process.
Charging Curve: 
Charging: CC red LED
Battery Full: CV green LED
