Tools battery packs are very useful as power sources on electronic projects and to just use around the show, powering small fans, lights etc, soldering irons, etc...There were few solutions on Thingiverse to create some sort of power supplies or battery adapters using Dewalt batteries, but none used a proper PCB and battery connectors.I made this one using proper battery connectors and a nice 3d printed case. Specially to power a fan as a fume extractor and my TS100 soldering iron. Original Dewalt batteries should have a proper BMS inside the battery, but the battery is always connected to the terminals of the battery so there is no way that the BMS can cut off current if the pack voltage is low. It's up to the tool to determine the cutoff point and you to properly charge the battery. Over discharging the battery can damage the cells.