This board forms part of a 9 * 18650 battery charger using 3 INA3221 chips to capture the voltage/current during charging. The I2C INA3221 register data is written via the WEMOS PRO MINI to an INFLUX database every 10 seconds. The data is surfaced through a GRAFANA dashboard. Each INA3221 has its own I2C address hardwired through links to the A0 pin i.e. (0x40, 0x41, 0x42) More information on the INA3221 can be found in the datasheet http://www.ti.com/lit/ds/symlink/ina3221.pdf The other main components are 9 TP5000 charging modules and a buck converter supplying the overall power to the converters. Screen capture only showing 6 batteries for clarity, but you get the gist of it.  Capturing this data may appear overkill for non data junkies. I will post the complete design, and would appreciate anyone willing to QA future designs before fabrication. Sample code base on Github https://github.com/GrahamOB/Arduino-IN3221.git