How to Connect Two 12V Batteries in Series
- 1). Assemble the batteries end to end. Ensure all batteries are the same type (Ni-Cad, Aluminum, etc.) and of equal charge. It is best to use batteries purchased at the same time, fresh from the box.
- 2). Ensure the batteries are connected in a positive-to-negative chain. This means that the end of the battery with a (+) sign must be connected into the (-) end of the next battery. This is why the connection is called a "series," as opposed to "parallel," where the batteries are lined up side by side. You can also check the terminals themselves: positive terminals have a small protuberance, which fits into the indentation or onto the flat of the negative terminal.
- 3). Connect the batteries to the appliance or circuit in which they are to be used. If the batteries are to be used in a store-bought device such as a flashlight or shotgun microphone, simple slide them into the battery compartment, making sure to maintain the serial order. If the batteries are to be used in a home-made circuit for hobby electronics or a DIY project, connect them into the circuit using copper wire. Make sure the positive terminal of the end battery is connected to the negative terminal within the appliance or circuit in which the batteries are to be used.
