I have a Sparkfun Fio v3 running off of a lipo battery.
The Fio is the brains for a small RC rover running two 6v micro gear motors controlled by a DRV8833 motor controller. Because the current draw is more than the Fio can put out I have a AA battery pack powering the motors and controller. The Fio just has a few pins attached to the controller board but I know how a common ground is preferred or required. What I don’t know is can my two different power sources (lipo + AA pack) share a ground?
Hello Ryan.
Yes, 2 batteries can share the same ground. It’s pretty common in electronics for all your parts to share the same ground but there are times when grounds are not shared.
Hello Ryan,
Yes, they can share the same ground. In batteries, when the two poles are connected (+ and -) there’s a potential voltage between these points. When only grounds are connected that potential difference isn’t exactly there.
What this means is that when the current is flowing between three points [as shown in the picture below] either battery pack will only “take” or receive their own respective current amount spent on their own circuits. This is because the conservation of charge is obeyed, what goes in must come out.
Thank you! This helped a bunch.