Lithium-Ion Battery Bank

June 2019 - August 2019

A portable battery bank with adjustable direction and speed for a small drill. The battery is in a 3S1P configuration to obtain a 11.1V nominal voltage. It is boosted to 17V via a boost converter to maintain a constant voltage. This 17V voltage is varied via LM317 adjustable voltage regulator to vary the motor speed between 1.25V - 14.5V. A DPDT switch is connected in series to allow direction switching. An LM324 Op-Amp utilized as a crude comparator is used to divide the battery voltage level into 4 levels as indicated by the 4 LEDs to represent state of charge. A Zener diode is to ensure a constant 12V reference voltage for the LM324.

The casing was designed on Autodesk Fusion 360 and 3D printed on a Prusa MK3S printer using PLA filament. It is comprised of three parts: front panel, housing, and cover.