How to Choose the Proper Battery for Your Solar Application

Twelve volts, 24 volts, or 48 volts?

On many occasions, the size of the system that you are making dictates the voltage based on your component configuration. Choose your voltage carefully since it can be difficult to change after you built your system. Here is a quick guide to help you determine which battery voltage is best for your system.

12-Volt Battery Systems

A 12-volt battery is more common in smaller systems and standard in vehicles like RVs and golf carts. If you’re putting a solar array on your van, RV, or skoolie, odds are you’re going to be using 12V batteries.

• Simple and standard in most vehicles, RVs, and boats
• For small, simple power systems
• Can be used directly in very small systems or add 120 volt AC with an inverter
  

 24-Volt Battery Systems

For larger systems like off-grid cabins, 24-volt batteries are more common. You can run wires longer distances which is more common in off-grid setups where you need your array on a ground mount away from your cabin.

• Use with systems of more than 720 watts of solar modules
• Most power changes to 120 volt AC power. Voltage converters are available to run 12 volt DC equipment from 24-volt batteries
• Wires can run longer distances, use to accommodate:

             - Solar modules over 75 feet from your home
             - Wind generator or hydro turbines over 300 feet away

48-Volt Battery Systems

For larger and more powerful systems, 48-volt battery systems are the way to go.  Anytime you need wiring to run a long-distance (up to 400 feet) 48-volt systems are necessary. 

• Use with systems where wire runs of up to 400 feet are necessary to reach the only good solar location
• 48-volt inverters are more robust and well-suited for larger power systems
• Converters are available to get 12 volts DC from a 48-volt battery system
• MPPT type charge controllers allow higher voltage solar arrays to transmit power more efficiently and from longer distances. You can place the array in the best location producing the most power possible. These controllers maximize the system’s output, saves wiring costs, and charge the lower voltage battery system (12, 24, or 48V).