Is ground wire positive or negative?
Is ground wire positive or negative? Ground is neither positive nor negative but it can *appear* to be either depending on how you define ground. Typically ground is an extremely low impedance path for current to flow and has a 0V reference voltage. This is done for several reasons, the most important of which is safety and circuit protection. Can you connect a battery to a ground line? Yes - just remember that your ground in that case will only be relative to the battery. If you go to connect this to another device (serial interface, etc) you need to...