Check out the diagram for more info. You can then connect each 6 volt pair in parallel with another pair to create a larger 12 24 or 48 volt battery bank.
How To Connect Two 12 Volt Batteries And Still Have 12 Volts
How to hook two batteries together for 12 volts. One way doubles the volts of the two batteries and the other keeps the same amount of volts. There are two ways to wire up two batteries. In parallel the voltage stays the same and in series it is doubled. There will be 24 volts about 28 volts with an alternator if two 12 volt batteries are wired together in series. Connect one of the battery cables to the positive terminal on battery number one. Connect the negative terminal of battery 1 to the positive terminal of battery 2.
How to wire two 12 volt batteries together. This is called a series parallel configuration. Make a series connection to the two 12 volt batteries. Connect the positive terminal of one battery to the negative terminal of the other. To produce a 12 volt output two 6 volt deep cycle batteries must be wired in series positive to negative. Following this example where there are two 12v 200ah batteries connected in series we will have a total voltage of 24v volts and an unchanged capacity of 200ah ampere hour.
Ground the negative terminal of battery 2. I have produced a diagram showing the connections for you. Attach the positive and negative terminals from each battery together. To wire two 6 volt batteries in series to produce 12 volts you would connect the load to the positive terminal of battery 1. The series connection of two identical batteries allows to get twice the rated voltage of the individual batteries keeping the same capacity. Each 6 volt battery pair operates as a single 12 volt battery.