Is it safe to short grounds of a battery, voltage regulator, and an ESC.


I am powering my Arduino with an ESC (of a quadcopter) (it outputs 5V) and I've also got a voltage regulator (LM2596) attached to my battery (14.4V 4S LiPo) for 3.3V components (as Arduino is unable to power all of them simultaneously).

I also need to measure my battery's voltage and I've made a voltage divider. However, when I measured the GND output of my voltage regulator and my battery's GND, they are very slightly different (in the range of microvolts). Should I short the grounds of the voltage LM2596, LiPo battery, and the ESC? Would it damage the Arduino? If I shouldn't, what is another good option to read battery levels directly (I mean using only a voltage divider) and safely with Arduino?


How is your voltage regulator able to work if it's ground is not connected to the battery ground? All wires and board traces have resistance and will show some voltage difference from one end to the other. Are you using an accurate enough meter to be sure of that low of a voltage?

All the grounds or more accurately, commons, must be connected for proper operation.


See here for why

The grounds of your battery and voltage regulator might be slightly different. If they are not physically at the same place, they represent two different points in a current carrying path, so a difference of a few microvolts sounds about right.

How is it that you have access to, and are using a micro-volt meter and are not familiar with 'ground-loops'?

Just asking. not germane to the question, to which the imperative answer is 'YES'.

If you are worried about it, try using a larger diameter/surface ground path, maybe zero guage solid silver buss??