Top 5 Best Solar Batteries (2024 Costs & Reviews)

What Should You Look for When Looking for Solar Batteries?

A lot of solar customers choose the Tesla Powerwall just because it’s the product they’ve heard about most often, and others may get shoehorned into a specific battery based on what their installer carries. We recommend choosing your battery carefully, even if it means installing panels with a different solar company.

Below are three things we’d specifically look for in a solar battery, along with a brief explanation as to why we think each is so important.

• Battery capacity: The storage capacity of your battery or batteries is a crucial thing to dial in. Oversizing your system means you’ll pay far more than you need to for backup power. Undersizing your system means you’ll only be able to power your home—or certain items in your home—for a short amount of time during an outage. It’s also important to note that solar batteries are becoming more prevalent as net metering policies decline across the country, as they recently did in California in mid-2024. Without net metering, solar batteries become the only way to maximize solar savings. If you want to make sure you save around the national average — $31,513 — you should make sure your capacity is large enough to offset consumption even when your panels aren’t producing enough to sustain your electricity usage.

• Power output: Most customers forget to consider the continuous and peak power ratings of their batteries. These numbers ultimately determine how many electronics and appliances you can run in your home at once on battery power. A rating that’s too low might not meet your energy demands and could end up damaging your batteries.

• Islanding inverter: A lot of the big-name solar batteries include islanding inverters, but not all of them do. Under normal circumstances, your panels will not provide electricity to your home in the event of a power outage to avoid dangerous currents running through utility lines when workers are restoring power. An islanding inverter lets you separate your photovoltaic (PV) system from the grid entirely so that your panels can recharge your batteries even during an outage. That means you can stay off-grid for much longer than you otherwise would, making the most use of your batteries’ capacity.

Compare the Top-Rated Solar Battery Manufacturers

The solar battery manufacturer you opt for can determine the warranty you get with your equipment, the customer service you’ll experience in the event of a warranty claim, the overall quality and reliability of the battery and more.

Based on the company’s reputation alone, we’d recommend Tesla and SunPower. Tesla is well-known for providing advanced technology, and SunPower is one of the most trusted and reputable companies in the solar industry.

The table below includes a look at how these companies and the ones we’ve reviewed above compare to one another. Keep in mind that these scores are determined using average numbers for each specification we consider if the provider offers more than one battery option.

Compare the Top-Rated Solar Batteries

In addition to considering the manufacturer of your solar battery, it’s, of course, important to compare the batteries themselves to make sure you get one that meets your needs. Overall, our top recommendations are the Tesla Powerwall (including the Powerwall+, the Powerwall 2 and the Powerwall 3, which is coming out in 2024) and the Panasonic EverVolt. The table below includes a comparison of these batteries and the other options we’ve reviewed above.

What Do the Solar Battery Specs Even Mean?

Looking at the battery specifications we’ve mentioned above can quickly get confusing. Not only are there a bunch of specs that vary pretty widely, but it’s also not apparent what each of them even means. Below, we’ll clarify what some of the less obvious specifications above mean and why we feel each is an important consideration.

• Per-battery capacity: The per-battery capacity tells you how much energy storage you get with each battery you install. The lower this number, the lower the barrier to entry into solar batteries as a whole. However, it’s important to consider this number in combination with the per-battery cost to see what you’re paying for each kWh. The SunVault from SunPower provides the highest per-battery capacity of our top picks by far.

• Total capacity in series: Many manufacturers let you install multiple batteries stacked together for greater total energy storage to provide more backup power to your home. The higher this number, the longer your system will be able to maintain power in your home through blackout conditions. Tesla lets you link 10 batteries together in parallel, providing the highest capacity in series of our top battery options — up to 135 kWh. To put that into perspective, the average home in the U.S. consumes 881 kWh per month, which means the Powerwall series could sustain full power for around 5 days, and that’s without any additional input from your panels. With your panels continuing to produce and charge them, you could potentially last indefinitely without power from the grid.

• Price per kWh: The price per kWh is straightforward, but it’s something many solar customers overlook. The cost per battery is important, but the per-kWh price is more important for determining the value you get for your money. The Powerwall Plus has the lowest price per kWh of the options we’ve reviewed.

• Continuous power output: Continuous power rating tells you how much power your battery can continuously put out over long periods. The higher this number, the more likely your battery will be able to provide electricity to your entire home, including all appliances,  electronics and even an EV charger. A lower output could mean the battery is only suitable for emergency power in an outage. The Panasonic EverVolt has the highest continuous output of the options above.

• Peak power output: Peak power ratings are similar, but they tell you the highest amount of power your battery can put out without sustaining damage. The higher this number is, the more likely your battery will be to keep up with high demand during blackouts without losing efficiency. Panasonic’s solar battery also scores highest in this category.

• Depth of discharge (DoD): This spec tells you how much of the battery’s storage can actually be used to power your home. The closer this number is to 100%, the more usable capacity you’ll have per kWh indicated in the battery’s nominal capacity. For example, a 100% DoD on a 10 kWh battery means you have 10 kWh of storage. A 90% DoD on that same battery means you effectively only have 9 kWh of storage. The batteries from Tesla and Panasonic have the highest DoD at 100%.

• Round-trip efficiency: Round-trip efficiency tells you how much of the solar power being routed to your battery will actually be available for storage. All batteries lose some of the energy generated by your panels, but the higher this number is, the less energy you’ll lose in the transition to storage. Higher efficiency ratings are best in areas where energy costs are high and where you don’t have access to net energy metering (NEM), as they will help maintain more of the power your panels generate to offset utility bills. The Generac PWRCell has one of the highest round-trip efficiency ratings in the industry at 96.5%.

Best Solar Financing

4.5/5

National CoverageManufactures Original PanelsA+ BBB Accreditation

Get Free Quotes

What Are the Benefits of Solar Batteries?

Solar batteries are expensive — usually adding between $10,000 and $20,000 to an already high solar installation cost of $29,970, on average, in the U.S. — and can often double your solar installation costs if you want full backup capabilities for your home. As such, many solar customers wonder if solar batteries are worth it. Below are a few of the most significant benefits they provide:

• Backup power during outages
• Effective net metering
• Energy independence
• Reduced carbon footprint
• Improved home value

We’ll explain each of these benefits in the following sections.

Backup Power During Outages

The most obvious benefit you’ll see from your solar batteries is the backup power they provide during blackouts. Having a solar battery or series of batteries installed gives you peace of mind that you’ll be able to maintain emergency power—for things like refrigerators, freezers and medical equipment—no matter what happens.

PV batteries are especially beneficial in areas where extreme weather is common. If you live in a state where hurricanes, tropical storms, tornadoes or other severe conditions frequently lead to blackouts, a backup power option that you can charge for free with your panels is a must-have.

Effective Net Metering

The biggest benefit to having solar panels for many solar customers is the savings on energy bills, but panels can’t always offset your electricity consumption. Panels see reduced or eliminated production on cloudy days and at night, which means you’ll have to pay the retail rate for any consumption at that time, provided you don’t have access to net energy metering.

Solar batteries provide effective NEM since you can store energy for later use if your panel production ever drops below your energy demands. Batteries can save thousands of dollars over their lifetime, especially if your state or utility company doesn’t offer net energy metering and you live in an area with above-average electricity rates.

It’s worth mentioning that California recently pushed out net metering 3.0, which decreased the credit rate for exported electricity. This is a big deal because California is the #1 state for solar in the country by a decent margin, so its policies are influential, to say the least. The likelihood is that the decreased net metering trend will continue in other states as well, which will make the effective net metering you get from solar batteries all but necessary to see a fast solar panel payback period and decent net profit from going solar.

Energy Independence

Since solar batteries provide effective NEM, they can often mean total energy independence if you also have panels installed.

That not only means that you don’t have to rely on a utility provider to deliver electricity, but, more importantly, that you don’t have to deal with increasing energy prices. Electricity costs in the U.S. have increased nearly 10% over the last year alone, according to the Bureau of Labor Statistics (BLS).

Energy prices are expected to continue to go up in the future, too. Your batteries will save you even more than expected because they offset energy consumption for which you would otherwise pay increasing prices.

Reduced Carbon Footprint

Another huge benefit of going solar is reducing your carbon footprint since most energy producers rely heavily on burning fossil fuels to generate the power they distribute. If you just have solar panels installed, your consumption on cloudy days, at night or during times of high demand will still rely on fossil fuels.

When you install a solar battery system, you’re far more likely to become totally independent from your power company. That means you’re contributing less to fossil fuel consumption and pollution, and you’re further reducing your CO2 emissions.

Improved Home Value

Finally, installing panels alone is estimated to boost your home value by around 4.1%. This is substantial, but most buyers are likely to see the increased benefits of your home being equipped with backup power as well. That will likely lead to buyers being willing to pay even higher prices for your property.

How Do Solar Batteries Work?

Solar batteries work just like other lithium batteries, except they get recharged most of the time with energy from your solar panels.

In a DC-coupled battery, the DC power coming from your panels creates a chemical reaction inside the battery, causing the lithium ions to release electrons. In an AC-coupled battery, the DC solar energy is converted in an inverter to AC power, and then excess energy is converted back to DC in another inverter. When the battery is called on for power, the energy is inverted a third time to AC power to be used in the home.

Generally speaking, DC-coupled batteries are more efficient than AC-coupled batteries because the energy only needs to be converted once, as opposed to three times. This reduces the amount of electricity lost in conversion.

Those free electrons then travel back and forth between the positive cathode and negative anode, depending on which direction energy is moving. The chemical reaction inside the battery is how those free electrons get stored for later use.

4 Types of Solar Batteries

There are four different kinds of solar batteries available for residential use:

• Lithium-ion batteries
• Flow batteries
• Lead-acid batteries
• Nickel-cadmium (Ni-Cd) batteries

We’ll explain the differences between each of these below.

Lithium-Ion Solar Batteries

Lithium-ion is the most prominent battery technology in the industry. You’ll often see these batteries listed as “lithium iron phosphate” batteries, LFP or LiFePO 4.

LFP batteries boast the highest battery capacities and have the longest-lasting battery lifespan of all of the options. They also require virtually no maintenance. These are best for solar customers looking for high performance, durability and longevity.

LFP batteries are more expensive than most other types of solar storage systems, which is the biggest downside.

Flow Solar Batteries

Flow batteries are a newer technology being used in the industry. They contain an electrolyte liquid that flows back and forth between storage tanks, which causes a similar reduction-oxidation (redox) process that you see in a lithium-ion battery. Flow batteries are also maintenance-free, and they come with the lowest risk of fire.

Flow batteries all have a 100% DoD, so you don’t lose any of the battery’s nominal capacity. They’re also some of the most durable options available.

However, they’re currently the most expensive since they’re an emerging technology, and the physical size of the battery needs to be large to reach the capacity and power output of lithium-ion batteries.

At this point, we only recommend flow batteries for solar customers who only want emergency backup power and are looking for a long battery lifespan.

Lead-Acid Solar Batteries

Lead-acid batteries are deep cycle batteries that are the most affordable option, primarily because they’ve been around the longest, so the production process is dialed in. The materials are also more affordable than lithium.

Lead-acid batteries are reliable and affordable, but they have a low DoD and a shorter battery lifespan than most other options. They also need regular maintenance and have some installation restrictions due to the potential for leaking.

We recommend these batteries for solar customers who are looking to keep upfront costs to a minimum.

Nickel-Cadmium Solar Batteries

Nickel-cadmium batteries are less prevalent than they used to be because cadmium is a toxic element. Most solar battery manufacturers have abandoned this technology in favor of lithium-ion.

Still, Ni-Cd batteries have excellent durability and are the best suited to operate in extreme temperatures. We recommend staying away from these unless you have no other option based on the climate where you live.

Nickel-manganese-cobalt (NMC) batteries also exist, but the manganese is also toxic, so these are also not prevalent in the industry.

Bottom Line: What’s the Best Solar Battery for You?

There isn’t one single battery that will be best for every solar customer. We suggest you consider a few different performance specifications when choosing a battery, including the per-battery and total capacity, the price per kWh, the power output, the warranty coverage and more.

Our top recommendations are the Tesla Powerwall + or the Tesla Powerwall 2, which we believe live up to the hype. These are the most popular solar batteries, though, and it might be overpowered for your home, depending on your expectations. However, the high capacity might be ideal for you if you live in an area without net metering, as batteries help boost your solar panel value, pay off your equipment more quickly and secure a net profit from your system.

As such, we recommend getting a few different quotes that include an array of solar battery options to make sure you’re getting the one that’s best suited for you. You can use the tool below to get multiple free solar battery quotes from providers in your area.

Methodology: How We Reviewed the Best Solar Batteries

We looked at every major solar battery available in the industry and compared them all based on six main categories and 17 individual metrics. We then weighted each spec, keeping in mind how impactful it would be to your experience. We’ll explain our six rating categories below.

• Battery capacity (20%): We first consider the per-battery capacity and the total capacity you can install in series. Higher capacities mean more backup power for your home, which can save you more money and provide greater peace of mind during blackouts.

• Price (20%): Cost is always going to be important, especially when batteries often cost close to $10,000 and are typically installed alongside a $20,000+ solar array. We consider the cost per battery for accessibility and the cost per kWh for overall value.

• Power and performance (25%): We look at five different performance specifications to find the solar batteries with the greatest power output to meet high energy demands and the highest efficiency to make your solar electricity go further.

• Warranty (20%): Most solar batteries have a 10-year warranty, but we also look at the efficiency degradation of each option to gauge longevity and durability.

• Availability (10%): Batteries with known lead time issues get ranked a bit lower than those with high availability. We also give extra points to batteries that can be installed by DIYers and those that can be installed independently of solar panels.

• Battery type and sustainability (5%): Finally, we rank each manufacturer based on the battery types they offer and the overall sustainability of the company. Lithium-ion batteries get the highest rankings, as they’re usually best for homeowners, and companies get extra points if they manufacture their products in the U.S.