A solar battery is an energy storage option for those with solar panel systems. With the increased use of solar power, solar batteries are more popular with homeowners who want to offset electricity costs and those living or camping off-grid. s you compare solar batteries, keep in mind that capacity tells you what the battery can store and is measured in kilowatt-hours (kWh). Power shows a battery’s output capability and is measured in kilowatts (kW). Look for a solar battery with a depth of discharge at least 40% or higher and round-trip efficiency around 80%.

Capacity: Capacity tells you what the battery can store and is measured in kilowatt-hours (kWh). The average American household uses about 30 kWh each day, and a typical solar battery has a capacity of around 10kWh.

Depth of discharge: The depth of discharge shows how much of your battery capacity can be used before potentially shortening its life span. The higher the DoD, the more usage you’ll get from the battery’s capacity.

Power: Power shows a battery’s output capability. The amount of power a battery can deliver at once is displayed in kilowatts (kW).

Round-trip efficiency: Round-trip efficiency is the difference between the amount of energy used to charge it and the available amount of energy. Like the depth of discharge, a higher round-trip efficiency percentage is a better value.

The last thing to consider is the battery’s warranty and guarantee. Since battery performance declines over time, a warranty that guarantees a number of cycles or years of good performance is essential. It should also guarantee the battery maintains a specific capacity.

Solar generators and portable solar chargers are types of solar battery storage systems. While solar generators are typically affixed to their location — usually houses, campers or boats — a portable solar charger is a smaller, often hand-held device typically used to charge phones or other electronics. Some solar generators are available as all-in-one kits, but you can buy components separately as well.

Types of solar batteries

There are multiple battery types to consider when choosing solar batteries. Which type is best varies based on your needs and whether you prioritize cost efficiency, safety or environmental impact.

Deep-cycle battery

Lithium-ion battery

Lithium-polymer battery

Flooded lead-acid battery

Sealed lead-acid battery

Nickel-cadmium battery

Saltwater battery          

Solar gel battery

How do solar batteries work?

Solar batteries can be installed alongside your solar panel system to store the excess energy it produces. When the panels don’t produce power at night, you can use the stored energy instead. Many solar battery storage options come with an inverter to convert the stored DC power to the AC power you need, but some require you to buy the inverter separately.

You can then use it as a solar battery generator to power electricity needs. This helps people looking to mitigate electricity costs, prepare for disasters or be completely off-grid. Homes still on the electrical grid can offset their consumption with backup energy and run on battery power until the storage is depleted.

The amount of electricity a solar battery can deliver at once is measured in kilowatts (kW). Kilowatt-hours (kWh) refer to the total amount of energy utilized over an hour. The U.S. Energy Information Administration (EIA) states the average American home consumes 901 kWh per month, or 30 kWh a day. With a battery that provides 2.5 kWh, you would need 12 batteries for sufficient daily power.

Since solar batteries self-discharge, the stored solar energy depletes over time. The rate of self-discharge depends on the type and age of the battery. Newer batteries typically deplete at a rate of 1% to 2% per month, whereas older batteries could deplete by as much as 2% per week.

Residential solar panel arrays don’t usually require solar batteries. Still, solar panel battery storage lowers your utility bills, protects you from power outages and reduces your carbon footprint. If you already have solar panels, solar batteries work to store energy for the future. However, most popular solar batteries like Tesla Power wall and LG CChem RESU aren’t designed to go completely off the grid.

Are solar batteries worth it?

Solar batteries are an energy-efficient way to generate backup power. However, for those who just want to go off the grid, diesel generators might be cheaper in the short term. Solar batteries make a lot of sense if you live in an area where utilities are unreliable or if you want to go off the grid while using renewable energy. Solar batteries store excess energy produced by your solar energy system so that you can tap into it whenever your panels don’t produce enough electricity.