When measuring voltage with a digital multimeter (DMM), a complete circuit is necessary to obtain a reading. Touching the positive terminal of one battery to the negative terminal of another battery does not create a complete circuit, resulting in no voltage measurement. The DMM requires a small current to charge its input capacitance and drop voltage across its input resistance. An exception occurs when measuring AC voltage, where capacitive coupling can introduce a small AC voltage reading due to ambient electrical noise.
PREREQUISITESElectronics enthusiasts, electrical engineering students, and anyone interested in understanding voltage measurement techniques with digital multimeters.
lundyjb said:So i was dinking around with my multi meter and i noticed that if you touch the positive end of a battery and the negative end of a different battery, there isn't a voltage being measured. Why is that. I would think that an excess of electrons would want to rush to any area that had a depletion of electrons, even if it wasn't in the same battery.