Batteries - continued

The top part of this figure illustrates how two batteries can be connected to oppose each other. In this series connection, the anodes of the two batteries are connected together as shown here. In this connection the two batteries work against each other. The net voltage which pushes current through the resistor is going to be:

12 – 5 = 7 Volts

To simplify the diagram we can replace the two batteries with one smaller one – as shown in the lower diagram.

Notice that the direction of the current is consistent with the larger battery. This is so because the effect of the 12 V is negated by the little battery to some extent, but since it is larger, therefore the direction of the current stays the same.