Lithium Batteries Capacity tester. 1v – 40v up to 10A.
Video how it works:
The idea of this tester is that I could use it with different voltage lithium cells 1 to 40 volts and even with cells connected into the complete pack. Also when discharging battery I can use high current up to 10A and even use real load like AC inverter or Grid Tie inverter.
Discharge testing:
When testing discharge according to your needed current, calculate resistor or other load. Set minimum cut off voltage with “set” button and potentiometer, you do not want to over discharge lithium batteries. Then press “start button”.
Charge testing:
In charging mode it will not calculate capacity properly, but may work as a cut off voltage protector. Connect power supply instead of load, set max cut off voltage with “set” button and potentiometer. Then press “start button”. That way you will not overcharge battery cell. Might be useful when testing car battery cells, charging cell directly with no bms with high current.
Arduino Nano code:
NOTE: I would not recommend to use ACS712 current sensor, for me it was unstable and not very accurate. Also do not do a mistake as I did, DO NOT place electromagnetic relay near ACS712 hall effect sensor. And also please use Fuse rated for correct current.