Hi, I wired a 24V battery --which were actually two 12V in series-- parallel with a 12V battery. The Voltage turned out to be about 18Volts when I measure the 12V Battery side. When I measured the 24V side, it turned out to be about 22.2Volts. What is going on? Why does the voltage change when different sides are measured? How would I go about calculating voltage when the batteries are in parallel and have different voltages?