I need to monitor the charge condition of an 8V lead acid battery.
For monitoring purposes, I used a Beagle Bone Black (BBB) running Linux. It is also supplied via this battery. The battery also supplies three DC motors (switching on and off) and a camera.
Now if the charge falls below a certain percentage, the BBB should report this via SSH and shutdown.
Now my problem is:
How can I determine the state of charge? Is it sufficient to measure voltage every ~50ms and report "Low power" when the voltage is below a certain value for 1s, or do I have to use a fuel gauge IC like this one? If so, which one is easy-to-use or has a tutorial or reference project I can stick to?