Measure Battery Voltage using SAADC and Convert to Battery Percentage

[epice500]

I am developing a small rechargeable device using an nrf52810. The device is powered using an LIR2032 coincell battery at 3.6 volts. I have been using the SAADC example as a guideline for how to take measurements on VDD. I would like to know how to convert this value into something that I can use to calculate the percentage left in the battery. I have been using a calculation that I found in another post to preform this, it is as follows: BatteryInMilliVolts = (((ADC_VALUE)(REF_VOLTAGE)) / 1024) * 6, but I am unsure if this is giving me an accurate result. Are there any examples which show how to preform this? 

Thank you

[Edvin]

Hello,

Please note that your battery has more than 3.6V maximum power. Just make sure that you are not feeding more than 3.6V into the nRF, or it may become defect. 

Looks like you are close. Remember to multiply ADC_VALUE and REF_VOLTAGE (looks like you are missing a "*").

What do you see? Do you see a reasonable number? Did you measure the actual voltage to compare with your ADC readings?

Best regards,

Edvin