#56 DIY VOLTAGE DIVIDER
In order to measure the voltage of a DC battery we will need a voltage divider sensor. I built an easy DIY voltage divider which works quite well. All we need are two resistors to measure the voltage in a certain way so our Arduino doesn’t fry.
After working out my requirements for a 12v 7Ah battery I came to the conclusion that I needed a 30k and a 7.5k resistor. This will allow me to measure DC voltage from 0.025v to 25v.
I only had to break the connection on the trace where the screw terminal was soldered to.
After creating a simple Arduino sketch I was able to output the data to the serial monitor. I had to add the correction factor of -0.150 to get an accurate reading after checking with two multimeters.
I used the Arduino pro mini as the MCU of this project.