What is it?

Battery Monitoring board with switches and LEDs for use with Arduino 2650 Arduino Uno, stacks as a normal shield. Useful for stationary batteries, used/new battery capacity/balance testing, cell level over/undervoltage cutout, sensing part of DIY cell balancer. Jumpers to isolate 9s tap for voltage sense amplifiers.

NOTE: THIS DOES NOT DO CELL BALANCING ON IT'S OWN.

IO pins to arduino. IO10 = A Cell select bit 0 IO11 = B Cell select bit 1 IO12 = C cell select bit 2 Any two of A0 to A5 for reading cell voltage.

Outputs used in supplied Arduino code. IO7 = Warning buzzer. IO8 = Cell/Battery overvoltage (low for overvoltage) IO9 = Cell/Battery undervoltage (low for undervoltage)

Power: 5V USB or DC input for Arduino/BMS board. 38V (9s tap) for voltage sense amplifiers OR external DC-DC PSU module.

Cell voltage graphed by copying data from Serial Port log into a CSV, then importing into https://plot.ly/create/ Could also use Excel, or any of the other programs that can graph data from CSV files.

Why did you make it?

I wanted a battery cell monitor that wasn't tied to a specific chemistry, or cell count, and has easily modified code. The omission of cell balancing components is on purpose, it's easy enough to add 1 mosfet, one power resistor per series cell and connect to Digital IO.

What makes it special?

One of only a few boards that are based around Arduino, but this is entirely one PCB, rather than one per cell with complex signal isolation. and can be used with Lithium Ion, Lithium Ion Phosphate, or Super Capacitors. Monitor up to 14 cells using just 3 IOs and 2 Analogue inputs.