Accurate low-cost expanded-scale analog voltmeter with novel charge/discharge indication for monitoring single Lithium-ion cells

摘要

This manuscript presents a very low-cost circuit using a PIC12F683 microcontroller and an LM285 bandgap voltage reference that provides an expanded-scale to an analog panel meter suitable for monitoring a single Lithium-ion battery. Charge or discharge of the cell is indicated by periodic twitches of the needle to the left or the right. The design is especially suitable for small devices subject to intermittant use or that recharge by power-harvesting. The design is open-source, with circuit, board layout, and source code provided.