Parallel Connection of Batteries

The figure provided here shows how two batteries may be connected in parallel to each other. Notice the following:

a. Two batteries can only be connected in parallel to each other if their voltage rating is identical. Remember, in the series circuits we were able to connect two batteries in series irrespective of their ratings. You cannot do that in parallel circuits. In this case we have two 12 volt batteries connected in parallel to each other.

b. In this configuration, the current being drawn by the resistor is 12 amps. Notice that 12 amps flows in and out of the resistor. But since the two batteries are in parallel to each other, they share the load. Each one of them supplies 6 amps – as shown. For ease of understanding you can assume the current to be analogous to water flow in gpm (gallons per minute). To apply the analogy here, we can say that 12 gpm water is flowing to the load. The water is being supplied by two pumps connected in parallel to each other. Each supplies 6 gpm, for a total of 12 gpm.