When using the voltmeter, when the black probe is on the black side of the battery?
When using the voltmeter, when the red probe is on the black side of the battery?
When the black probe is on the black side of the battery, the voltmeter will not give an accurate reading as it is in reverse polarity.
When the red probe is on the black side of the battery, the voltmeter will also not give an accurate reading as the polarity is reversed.