Battery life characterization using ADC current


I am aiming to measure the capacity of a battery by discharging it quickly over a couple hours while measuring its output voltage and current.

Is it possible to do this by simply connecting it to the ADC pins, inputting a small resistance under the ADC Current project setting, and watching the ADC Current and ADC Voltage curves? It seems almost too simple. Am I missing something?

Thank you!

Hi and welcome to the forum.

Below is how you can connect to do this:

The battery will be discharged with constant resistance (Sense+Load) as soon as you have it connected, there is no stop button.
Enable ADC current channel and ADC voltage channel.
For ADC current, you need to specify the chosen sense resistor value to get the right current and discharged energy. For ADC voltage you will be able to graph the battery pole voltage during discharge.
You will introduce a ~10uA leakage into the ADC pins of Otii Arc but if you are discharging with higher current, then this can be disregarded.
ADC+ and AGND should be connected as close to the battery poles as possible, with other cables to the resistors, this to improve the measurement if you discharge with high current.

The accuracy of this setup is dependent of the resistance of the sense resistor. The higher resistance, the better accuracy. Sense resistor should be chosen so the shunt voltage is below 81.2mV (according to the Technical Specification

To work more with batteries, I suggest that you buy our Battery Toolbox

Best regards,