Having lithium cells or batteries in spare parts boxes — without being able to check their efficiency and actual charge capacity — is not that useful. This simple charger and capacity tester, based on two inexpensive modules commonly available on the market, effectively solves the problem. 

Background

While rummaging through the drawers in my workshop, I found several 18650 cells, some DIY battery packs with XH 2.54 and XH 1.27 connectors, and others. Therefore, I started looking for a quick and easy solution to charge and measure the capacity of all those lithium elements I had at hand.

Simple Charger and Capacity Tester
Figure 1: This IP2312 module variant allows you to adjust the end-of-charge
voltage and the charge current rate. Figure 2: The HW-586 discharge module
installed in the prototype.

I found two dedicated modules: one for battery charging, based on IP2312 from Injoinic Corp., shown in Figure 1, and one for processing discharge and capacity measurement — commonly known as HW-586 —...