What is the difference between 6 volt and 12 volt deep cycle batteries?
If you looked into choosing the right battery. Then you've learned about cranking, hybrid, and deep cycle batteries and you've learned about true deep cycle batteries.
But what about battery sizes... 6 volt verses 12 volt. Some say two 6 volt batteries are better than two 12 volt batteries.
First let’s look at the make up of each type of battery. Both are lead acid batteries, both contain 2.1 volt cells. Three cells in the 6 volt battery and six cells in the 12 volt battery. The 6 volt battery has more space per cell than the 12 volt hybrid so the plates are thicker and will last longer. The 6 volt will be able to discharge deeper than any hybrid 12 volt deep cycle. Two 6 volt deep cycle batteries are a much better buy than two hybrid 12 volt batteries.
I have two customers both having 420 amp hour (Ah) battery banks. One with four 6 volt deep cycle batteries and one with two 12 volt deep cycle batteries. Both perform equally well, so why did we choose one over the other? Size of the battery bay in the Rv's. One was tall and narrow and one was short and wide. This is where dimensional size comes into play.
If we installed two 6 volt deep cycle batteries in the tall narrow bay the customer would of only had 210 ah of storage capacity, so the 12 volt industrial deep cycle batteries were the best option for this customer.
But 6 volt batteries are a lot easier to handle at 50 to 60 pounds each. Rather than the 12 volt industrials at 110 pounds each.
When installing two 6 volt batteries wired in series the amp hours remain the same and the voltage is doubled. Example: Two 200 amp hour 6 volt batteries wired in series equals one 12 volt 200 amp hour battery.
When working with two 12 volt batteries wired in parallel the voltage remains the same and amp hours are doubled. Example: Two 100 amp hour 12 volt batteries wired in parallel, makes one 12 volt 200 amp hour battery bank.