Black and Decker USB charger

thingiverse

Update: Black and Decker batteries don't automatically shut off when they're running low - that feature is built into the tool itself. To prevent damage, you should install a voltage monitor or cutoff circuit, or simply use it for shorter periods. I constructed my project using ABS plastic and held the parts together with super glue. There's definitely room for improvement, but it works as intended. For the 20v to 5v regulation and USB connection, I used this product: https://www.amazon.com/gp/product/B01HXU1C6U/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1 I utilized crimped spade connectors that I had on hand for the battery terminal connections and pressed them into place. Then, I soldered short wires to the input of the regulator.