Solar batteries provide energy storage for solar, wind power, or other renewable energy systems. A solar battery is just a deep cycle battery - a battery designed for the prolonged, repeated, and deep charging/discharging cycles needed to store and distribute energy generated by intermittent renewable sources like solar panels. For this reason, car batteries cannot be used as solar batteries.
Grid tied systems do not need batteries unless you want to maintain power during utility grid outages. But for off grid systems, deep cycle solar batteries are essential and will likely be providing 100% of your electricity. This makes correctly sizing a solar battery bank among the most important steps of off grid system design - watch our video below for more.Read more +
A solar battery bank consists of one or more deep cycle batteries. Just like an individual battery, a battery bank’s energy storage capacity is measured in amp-hours (Ah) or kilowatt-hours (kWh). To determine how much capacity you need, use our kWh calculator.
In this video you will learn how to correctly size a solar battery bank.
We strongly recommend watching the solar battery bank sizing video above, but some of the key takeaways are:
After determining the capacity and voltage of your battery bank (12V, 24V, or 48V DC), you can start thinking about the specific deep cycle batteries that will make up the bank. Need help making those determinations? Call us at 877-878-4060 or request a free off-grid solar power system quote.
A deep cycle battery is the only kind of battery that makes sense for a solar or wind system, but what about the different types of deep cycle batteries - lithium, flooded lead acid, AGM, and gel? Which kind is best?
While it’s true that each different cell chemistry has its pros and cons, it’s also true that lithium batteries are easily the best choice for most solar panel systems. Compared to all the other chemistries, lithium batteries are deeper discharging, longer-lasting, lighter weight, safer, and maintenance-free. Yes, they are more expensive up front than the other types, but in the long run, the cost per kWh cycle is the best metric to look at - and with both longer cycle life and deeper Depth of Discharge than the alternatives, the cost per kWh cycle you’ll get from a lithium solar battery bank is unbeatable - and you won’t have to replace them as often.
Flooded Lead Acid
|Cost per kWh Cycle||Lowest||Low||Low to moderate||Moderate|
|Expected Lifespan||10+ years||3-5 years||4-5 years||5-6 years|
|Max Recommended DoD||80%||50%||50%||50%|
|Regular Maintenance||None||Watering, equalizing, cleaning||None||None|
|Best Applications||All renewable energy systems||Full-time residences with committed, hands-on owners willing to do regular maintenance and replacement||Part-time residences with intermittent use||Part-time residences without many high-surge loads|
|Worst Applications||Projects on a tight budget||Part-time residences with intermittent use||Systems requiring deep discharges||Systems requiring high-amperage charging and discharging|
If your solar power system is connected to the grid, it will shut down during grid outages as a safety precaution for the workers who will be repairing the utility equipment. To keep a grid tied solar system online during a grid outage, you will need to add a battery bank and a second inverter to create what is known as a hybrid solar system.
This video explains the two main ways to add battery storage to an existing grid-tied solar system.
Adding batteries to a grid-tied solar system is becoming increasingly popular - especially in areas where the utility grid is unreliable due to excessive demand (rolling blackouts) or frequent extreme weather events. For a new hybrid solar system or to retrofit an existing grid-tied system with battery storage, use our battery backup power system quote.