How does a 6 volt battery work?
What to know about using 6 volt batteries in your solar installation

When most people talk about purchasing batteries for their solar installation, they’re typically talking about using 12 volt deep cycle batteries. 12 volt batteries deep cycle batteries are the most common option available, but a 12 volt solar system can also be achieved by using a different combination of batteries. 6 volt batteries, often found in golf carts, have a few advantages over 12 volt batteries and are worth the consideration if you’re looking for a battery solution for a solar installation in your RV, camper, or van.



What are deep cycle batteries?

Deep cycle batteries look similar to car batteries, but are actually very different. In contrast to car batteries which only provide short bursts of energy, deep cycle batteries are designed to provide sustained power over a longer period of time. Deep cycle batteries can be discharged up to 80%, but most manufacturers recommend not discharging below 45%. Regularly going beyond that point will shorten the life of the battery.



How do solar batteries work?

Solar batteries store the energy that is collected from your solar panels. The higher your battery’s capacity, the more solar energy it can store. Battery banks are similar to a gas tank. The larger the tank, the further distance you can go between stopping at a gas station. However, a larger tank means you’ll spend more time at the pump as it fills up that bigger tank. In order to use batteries as part of your solar installation, you need solar panels, a charge controller, and an inverter.

Your solar panels will first need to be connected to a charge controller which will help monitor how much energy is stored in the batteries to prevent overcharging. Charge controllers will also shut down a system if the batteries become too depleted. Before providing power to your appliances, your batteries will need to be connected to an inverter to convert the DC energy collected from solar panels and converted to AC energy.

When using batteries for solar panels as part of a home solar system, you’re able to store the excess electricity your panels produce instead of sending that energy back into the grid. Electricity will be sent to the grid if your batteries are fully charged and your panels are still producing energy.



What’s the difference between 6 and 12 volt batteries?

Beyond the obvious voltage difference between 6 and 12 volt batteries, there are also a few other things that set them apart. When weight and cost are not important factors, and higher power is needed, you should go with 12 volt batteries instead of the 6 volt option.

6 volt batteries use heavier plates in each cell and typically have longer lifespans than 12 volt batteries. They can last anywhere from four to eight years, depending on maintenance, type, and use of the battery. Additionally, 6 volt batteries weigh less than 12 volt batteries, making them much easier to handle and move.



What are the different types of batteries?

There’s a range of deep cycle battery options.The most common ones used for solar installations are flooded lead acid, sealed lead acid (absorbed glass matt and gel), and lithium iron batteries. Flooded lead acid batteries are the most inexpensive option and are available at most big-box and auto stores. Sealed lead acid batteries store 10 to 15 percent more energy than lead acid batteries and charge up to four times faster. Lithium iron batteries are the most expensive options, but also last four times longer than lead-acid batteries and weigh much less. 6 volt batteries are most often available as flooded lead acid and absorbed glass matt options.



What are the pros and cons of 6 volt batteries?
    Pros of Using 6V Batteries
  • They have larger amp hour capacities: When fully charged, 6 volt batteries have larger capacities than 12 volt batteries. An Amp Hour (Ah) is the amount of current a battery can supply for a certain period of time. Using a battery with a higher Ah will improve the device’s running time on a single charge. This is important if your panels won’t be collecting energy for longer periods of time.
  • They have a bigger discharge and recharge capacity: This means that you can discharge and recharge the batteries more often than 12 volt batteries over the life of the battery.
  • With proper maintenance, 6 volt batteries can last much longer: You can expect 6V batteries to last anywhere between 4 to 8 years depending on how you take care of them and the specific conditions of the location where the battery bank is installed.

Cons of Using 6V Batteries
  • 6V batteries are more expensive based on the comparative capacity: If you are on a tight budget, you should probably purchase 12 volt batteries.
  • 6V batteries are much taller and may require you to install different battery boxes: RVs that already have battery boxes built in are designed to accommodate 12 volt batteries. If you will be using 6 volt batteries, they won’t quite fit properly in that allotted space.
  • They are uncommon and can be hard to find in case you need emergency replacements: If your batteries fail while you’re on the road, they’ll be hard to find. They’re typically only found at specialty stores and online.


How do you connect 6 volt batteries?

Knowing how to properly connect 6 volt batteries is very important. There are two main ways to wire batteries: in series and in parallel.

Connecting batteries in series adds the voltage of the two batteries, but it keeps the same amp hours. To connect batteries in a series, connect the negative terminal of the first battery to the positive terminal of the second battery. Use another set of cables to connect the open positive and negative terminals to your application.

You can connect two 6 volt batteries in series so that they can put out 12 volts of power. However, when you use batteries hooked up in series, it will only charge to the capacity of the battery with the lowest amp hour capacity.

Connecting batteries in parallel will increase your current rating, but the voltage will stay the same. To join batteries in parallel, connect both the positive terminals and another jumper wire to connect both the negative terminals of both batteries to each other. Negative to negative and positive to positive.

When two 6 volt batteries are connected in parallel, their combined voltage will still be 6 vols but their amp hour capacity will be equal to the sum of the capacity of the batteries.



Can you use a 6 volt battery with a 12 volt solar panel?

Not on its own. When you want to charge a 12 volt panel, you’ll want at least a 12 volt battery bank. So you can still use 6 volt batteries to charge that panel, but you’ll need at least two batteries that are connected in series.



Can you use a 12v solar charger on a 6v battery?

Again if you have two 6 volt batteries connected in series, you can use a 12 volt battery charger. However, we do not recommend using a 12 volt battery charger if you only have one 6 volt battery.



Can I produce a 24v or 48v system with 6 volt batteries?

Yes, as long as you’re wiring your 6 volt batteries in series, they’ll add up to the desired voltage. However, if you need a larger 48 volt system, it would probably be wise to purchase larger voltage batteries to save weight and space.



How much does a 6 volt battery cost?

Depending on if it is flooded lead acid or absorbed glass matt, 6 volt batteries cost between about $100 and $800.



Conclusion

6 volt deep cycle batteries can be used in a variety of applications and can be connected in series to power 12, 24, and 48 volt systems. The main advantage of using 6 volt deep cycle batteries instead of 12 volt batteries is to achieve increased amp hours to power your RV, van, or camper. Using a battery with a higher amp hour rating will improve the device’s running time on a single charge. However, 6 volt batteries have different dimensions than 12 volt batteries, you’ll need to purchase more batteries to assemble a battery bank for a larger solar installation, and they are more difficult to find than 12 volt batteries. By taking these advantages and disadvantages into consideration, you’ll be able to make the right choice for your solar installation.