How should two 6-volt batteries be connected to achieve a total of 12 volts of direct current?

To achieve a total of 12 volts of direct current using two 6-volt batteries, the correct method is to connect them in series. When batteries are connected in series, the voltage outputs of each battery add together while the capacity (amp-hours) remains the same as a single battery.

In this case, connecting the positive terminal of the first 6-volt battery to the negative terminal of the second 6-volt battery creates a 12-volt circuit, providing the desired voltage for many RV appliances and systems. The remaining terminals, one from the first battery and one from the second battery, can then be connected to the power system.

In contrast, connecting batteries in parallel would keep the voltage the same as a single battery (6 volts), which is not the target in this scenario. Therefore, using the series connection enables the batteries to deliver a higher voltage output suitable for various applications in RVs.