If you have a solar panel system, solar batteries can help you get the most bang for your buck. These batteries store excess energy that can be used when your system isn't working optimally, like during power outages, on cloudy days, or at night.
To help you narrow down your search, we’ve compiled this list of the best solar batteries for storage. We've taken into account important factors like battery capacity, power rating, and affordability to make your decision easier.
Keep reading to learn more about the best batteries for solar power storage based on our findings.
Tables of Contents:
- How We Chose the Best Solar Batteries
- The Best Batteries for Solar Power Storage and Their Rankings
- What Is a Solar Battery and How Does It Work?
- What Are the Benefits of a Solar Battery?
- What Are the Different Types of Solar Batteries?
- Best Solar Batteries FAQ
How We Chose the Best Solar Batteries
There are many factors to consider when selecting a solar battery. Here's what we took into account during our evaluations.
Capacity refers to the amount of energy the battery can store, and is measured in kilowatt-hours (kWh). A battery that holds more energy will be of greater value.
Power measures the output of energy the battery can produce at any given moment, and is measured in kilowatts (kW).
Round-trip efficiency shows the difference between the amount of energy used to charge the battery and the amount of energy available. A higher round-trip efficiency translates into better value.
Depth of discharge
Depth of discharge (DoD) refers to how much of the battery's capacity can be used. A battery with a higher DoD will allow you to use a greater percentage of its capacity.
A solar battery can range in price from a few thousand to tens of thousands of dollars based on the above factors. However, keep in mind that prices may vary depending on the vendor you purchase the battery from.
A warranty can help ensure that a battery lasts as long as the manufacturer guarantees. Most solar batteries have a warranty period of around 10 years, so we used that as a benchmark during our evaluations.
The Best Batteries for Solar Power Storage and Their Rankings
Now that you know how we came to our conclusions, let's get into our rankings of the best batteries for solar power storage.
|Battery||Rank||Price||Warranty||Capacity||Power||Depth of discharge||Round-trip efficiency|
|Tesla Powerwall 2||Best overall||$11,500||10 years||13.5 kWh||5 kW||100%||90%|
|Enphase IQ Battery 10||Best warranty||$9,000||10 years with an optional 5-year extension||10.08 kWh||3.84 kW||100%||96%|
|Panasonic EverVolt 2.0||Most powerful||$17,000||10 years||17.5 kWh||9.6 kW||100%||90%|
|LG Energy Solution RESU 10H Prime||Best value||$8,000||10 years||9.6 kWh||5 kW||100%||95%|
|BigBattery 48V Kong Elite Max||Highest capacity||$10,100||10 years||19 kWh||7.5 kW||95%||N/A|
Best Overall: Tesla Powerwall 2
Tesla Powerwall 2
Average price: $11,500
Warranty: 10 years; unlimited cycles
Battery capacity: 13.5 kWh
Depth of discharge: 100%
Round-trip efficiency: 90%
Power: 5 kW
- High battery capacity
- Modern and sleek design
- Can monitor your solar energy from anywhere using the Tesla app
- No exposed wires make it child- and pet-friendly
- Included with purchase of Tesla solar panels
- Warranty covers unlimited cycles
- Tesla doesn't sell the Powerwall 2 individually
- Potentially long waitlists due to production delays
Why we chose Tesla Powerwall 2:
You've probably heard of Tesla because of the brand’s electric cars, but did you know they're also one of the leading producers of solar technology? Tesla creates top-notch solar panels and batteries to help you generate clean energy and power your home.
The Tesla Powerwall 2 is a lithium-ion battery system that stores solar energy as backup protection in case of outages or cloudy days. What sets this battery apart is its sleek design and compact shape which complements any space. The innovative Tesla app lets you monitor the battery and control your system from anywhere, and provides helpful alerts in the case of severe weather.
In terms of specs, the Tesla Powerwall 2 has a relatively high capacity and power rating, and its 10-year, unlimited cycles warranty ensures you'll be using it for a long time to come. The only downside of this battery is that it can be tricky to get your hands on, as it's not sold as a standalone by Tesla; however, you can reach out to a Tesla Certified Installer if you wish to purchase the battery independently. You can expect the Tesla Powerwall 2 to cost roughly $11,500.
Best Warranty: Enphase IQ Battery 10
Average price: $9,000
Warranty: 10 years with an optional 5-year extension; 4,000 cycles
Battery capacity: 10.08 kWh
Depth of discharge: 100%
Round-trip efficiency: 89%
Power: 3.84 kW
- Optional 5-year extension to the 10-year warranty
- Mobile app available for monitoring
- Compatible with most AC home generators
- Modular battery capacity
- Can connect with both gas- or solar-powered generators
- The Storm Guard feature alerts you in the case of severe weather
- Lower power rating
- Designed to be used with IQ8 microinverters
Why we chose Enphase IQ Battery 10:
The Enphase IQ Battery 10 is an AC battery system that includes three IQ Battery 3 storage units, which you can add onto if you require more storage in the future. The system uses lithium iron phosphate chemistry for long-term safety and reliability. Plus, you can monitor and control your battery from afar using their mobile app and receive weather updates from the Storm Guard feature.
What sets the Enphase IQ Battery 10 apart is its warranty, which offers an optional five-year extension, allowing you to be protected for a total of 15 years. The only downside of the Enphase IQ Battery 10 is its lower power rating compared to others on this list.
Most Powerful: Panasonic EverVolt 2.0
Panasonic EverVolt 2.0
Average price: $17,000
Warranty: 10 years
Battery capacity: 17.5 kWh
Depth of discharge: 100%
Round-trip efficiency: 90%
Power: 9.6 kW
- Highest power rating
- Can be both AC- and DC-coupled
- Intuitive EverVolt app
- Modular design
- Can be serviced directly in your home if needed
- Most expensive option
Why we chose Panasonic EverVolt 2.0:
You've probably heard of the brand Panasonic (one of the leading technology companies in the world) but did you know that their expertise extends to solar power? The Panasonic EverVolt 2.0 is a state-of-the-art battery storage system that can be AC- and DC-coupled, meaning it works seamlessly with both new and pre-existing solar panel systems.
While this battery is the most expensive on this list, it also has the highest battery capacity and highest rating, so you can ensure you're getting the biggest bang for your buck. Plus, the EverVolt app allows you to check your usage, backup power, net metering, and more from your phone.
Best Value: LG Energy Solution RESU 10H Prime
LG Energy Solution RESU 10H Prime
Average price: $8,000
Warranty: 10 years
Battery capacity: 9.6 kWh
Depth of discharge: 100%
Round-trip efficiency: 95%
Power: 5 kW
- Most affordable
- Tried-and-true brand
- Lower capacity than others on the list
- Lower power rating than others on the list
Why we chose the LG Energy Solutions RESU 10H Prime:
LG Energy Solutions is a trusted brand and leading manufacturer of solar batteries, offering a 10-year warranty to back that up. The LG Energy Solutions RESU 10H Prime is the most affordable battery on our list, while still maintaining a relatively high battery capacity and decent power rating. The RESU 10H Prime is compatible with a variety of inverters, like SolarEdge, SMA, General Electric, and more. All in all, the LG RESU 10H Prime is an excellent value from a trusted source.
Highest Capacity: BigBattery 48V Kong Elite Max
BigBattery 48V Kong Elite Max
Average price: $10,100
Warranty: 10 years
Battery capacity: 19 kWh
Depth of discharge: 95%
Round-trip efficiency: N/A
Power: 7.5 kW
- Highest capacity
- Includes an LED Smart Display
- Affordable price
- Round-trip efficiency not available
- Brand is not as well known as others on the list
Why we chose BigBattery 48V Kong Elite Max:
The battery with the highest capacity on this list, the BigBattery 48V Kong Elite Max delivers a whopping 19kWh of capacity and 7.5 kW of power. The 48V Kong Elite Max also has an enhanced battery management system, which allows it to work efficiently in cooler temperatures. An LED Smart Display allows you to monitor the battery when you're away from home.
How To Determine the Best Solar Battery for You
There are likely to be some ranking factors that are more important to you than others. Below, we've outlined some additional tips to consider in order to choose the best battery for your specific solar needs.
Determine the Energy Needed in the Event of an Outage
As you can see, some batteries on our list have a higher capacity than others. In order to choose the right battery for you, we recommend taking a look at your energy usage to determine how many kWh your home requires in the event of an outage.
According to the U.S. Energy Information Administration, the average home uses roughly 30 kWh of energy per day. If you want two days of autonomy in the event of an outage, you'd need about 60 kWh of battery capacity. Depending on your energy usage and how many days of energy usage you wish to store, you may want to buy multiple batteries to meet your needs.
On the other hand, if you don't need stored energy in the event of an outage and just prefer to have it for days when your solar panels aren't performing optimally, a lower capacity battery may work well for your situation.
Take Into Account the Peak Load of Your Home
Another important factor to take into consideration is the peak load of your home, which will help you determine how much battery power to look for. If you frequently use a lot of electricity and run multiple devices at the same time, you may want a higher power rating. We recommend multiplying the wattage of each device by the amount of time it runs to determine how much power you might need.
Consider Your Budget
Before you choose the battery with the largest capacity and highest power rating, make sure your budget allows for it. If you have a tight budget, keep in mind that you can add more batteries to your system in the future when your budget is more flexible.
Which Is the Best Solar Battery for Your Home?
All in all, the right battery depends on your personal needs. However, we have a few recommendations based on our research into the best batteries for solar power storage.
If you're looking for a battery with a high capacity and power rating, we recommend the BigBattery 48V Kong Elite Max. While BigBattery is a lesser-known brand compared to names like Panasonic and Tesla, they are quickly growing into one of the largest U.S.-based battery manufacturers. However, if you'd rather go with a brand you know and trust, the Panasonic EverVolt 2.0 is another excellent option with both a high battery capacity and power rating.
Meanwhile, if you're budget-conscious or looking for a warranty that stands the test of time, we'd recommend the LG Energy Solution RESU 10H Prime or the Enphase IQ Battery 10. Both of these options are under $10,000, and Enphase offers an optional five-year warranty extension to give you additional confidence in your investment.
If you're looking for a combination of battery capacity, power rating, affordability, and brand reputation, the Powerwall 2 checks all of those boxes.
What Is a Solar Battery and How Does It Work?
Before you decide on a solar battery, let's go over what they are and why you may want one in the first place. Oftentimes, solar panels create more energy than your home requires at a given time. Solar batteries help prevent wasted energy because it can be used when the solar panels are not producing enough energy. If the solar panels are generating more energy than the home requires, the excess will flow into the battery and charge it for use at a later date.
What Are the Benefits of a Solar Battery?
So do you even need a solar battery? While solar panels don't require a battery to work effectively, there are some benefits solar batteries offer that you won't get with solar panels alone.
- Battery backup in the event of an outage: If you have a solar battery, your home will continue to run even in the case of a power outage.
- Energy bill savings: Installing solar batteries can help further reduce your electric bill by storing away energy to be used during peak rates.
- Reduces carbon footprint: Solar batteries prevent you from using energy from the grid, which emits fossil fuels.
What Are the Different Types of Solar Batteries?
There are four different types of solar batteries currently available. Let's take a look at each of these batteries.
The oldest type of solar battery on the market, lead-acid batteries were first created in 1860 by French physicist Gaston Planté. They work using a chemical reaction between lead and sulphuric acid. Today, lead-acid batteries are still used due to their reliability and affordability, however, they don't last as long as other newer batteries on the market.
Lithium-ion batteries were developed in the 1980s. While they are slightly more expensive than lead-acid batteries, they also have a longer life span and can hold more energy. As a result, most of the leading solar batteries on the market are lithium-ion.
A less popular choice for solar, nickel-cadmium batteries first came about in the late 1800s. However, they aren't as widely used today due to their negative environmental impact. Cadmium is extremely toxic, which makes these batteries hard to dispose of.
The most expensive type of solar battery, flow batteries involve the circulation of two electrolyte liquids between tanks. While flow batteries are newer to the scene, they have the longest life span and a 100% depth of discharge.
Best Solar Batteries FAQ
Choosing a solar battery can be a difficult decision. Below, we've answered some common questions about solar batteries to help you out.
How Long Do Solar Batteries Last?
Depending on the type of battery, you can expect most solar batteries to last between five and 15 years or more.
How Many Solar Batteries Do I Need?
The number of solar batteries you need will depend on how much energy your solar panels generate, how much energy your home requires, and the capacity of the battery. One way to determine how many batteries you need is to consider the kilowatt-hours your home requires in case of an outage and divide that number by the battery capacity.
Which Solar Battery Lasts the Longest?
Flow batteries last the longest with a typical 25-year life span.
Why Are Solar Batteries So Expensive?
Solar batteries are quite pricey, typically costing between $7,000 and $15,000, due in large part to the high price of materials and equipment needed to make them. The capacity, power, and other features of the battery also influence the price.
Ultimately, the best solar battery will depend on your solar needs. Luckily, Solartap features brands that create some of the best solar batteries on the market. Explore our selection of solar batteries today.