The 9 Best Solar Batteries of 2023
Home energy storage batteries have been on the market for many years with numerous varieties and sizes now available. Due to the rapid improvements in lithium cell technology, modern lithium battery systems quickly superseded traditional lead-acid batteries as manufacturers developed smart, modular systems to suit different energy storage applications.
Solar batteries store excess energy your solar panels produce to use at night, on cloudy days or during power outages. Adding them to your system allows you to use more of the solar energy you’re creating, reducing overall energy costs and maximizing your savings.
Best Overall
Amino New Energy Battery Co.,Ltd is founded in 2016 under the mission of making outstanding contributions to sustainable development and new energy innovative technologies, committed to providing premier solutions and services for new energy applications worldwide. The company is mainly engaged in Lithium Battery Pack; ternary polymer lithium batteries; energy storage cells and battery packs,accumulated rich professional experiences in such fields.
1.Goodwe Lynx U-Series
Goodwe was founded in 2010 and has earned a reputation as one of the top Chinese solar inverter manufacturers. The company was a pioneer in hybrid battery storage technology and has engineered a vast range of residential, commercial, and utility-scale inverters and numerous energy storage systems. GoodWe’s new Lynx Home U Series battery is a feature-packed, cost-effective battery system built using safe and proven lithium iron phosphate (LFP) cells. Each low-voltage (48V) Lynx battery has a total capacity of 5.4kWh with 90% usable or 4.8kWh. For additional storage requirements, up to six Lynx batteries can be connected in parallel to provide up to 28.8kWh of usable storage capacity.
Goodwe Battery specifications
Type: DC battery system - Lithium LFP cells
Size: 5.4kWh with 90% usable capacity
Power output: 2.5kW continuous, 2.9kW max peak - Power increases to 5.76kW with 2 or more batteries in parallel.
Cycle life: up to 4000 cycles (claimed)
Price: $3300 (US$2600)
Warranty: 10 years to 70% minimum retained capacity.
Compatibility: Goodwe Hybrid inverters: ES, EM, BP, SBP series
The Lynx battery system boasts a range of innovative features, including remote monitoring and software upgrades, plus the ability to identify additional parallel modules automatically, making setup effortless. More importantly, the Lynx battery can automatically reboot after entering self-protection mode due to an under-voltage event; this is a common problem on many batteries during a prolonged blackout when the battery is drained to very a low state of charge. In order to wake up and start charging after a low voltage event, many other managed lithium battery systems (using the standard CAN bus communications) need to be manually restarted via a specific startup procedure which can be problematic for an untrained user. Fortunately, this will not be an issue with the Goodwe Lynx batteries when coupled with a compatible Goodwe hybrid inverter.
While output power is limited to 2.5kW continuous using one battery, the power rating is increased to 5.76kW with two or more batteries in parallel. Generally, 2.5kW is adequate for a battery of this size and will cover most average household loads. More importantly, the conservative power rating helps increase battery life by limiting the internal heating of the cells during use.
2.SunPower SunVault
Known for its high-efficiency solar panels, SunPower developed a solar battery in 2019. It’s one of the highest capacity batteries on this list and uses the latest LFP battery chemistry, making it more powerful and long-lasting.
Pros and Cons
Here are the pros and cons of the SunPower SunVault:
+ Boasts one of the largest usable capacities on our list
+ Offers two battery options for more customization
+ Uses LFP technology for longer battery life and improved safety
– Doesn’t provide depth of discharge information
– Only works with SunPower solar panel systems
SunPower SunVault Details
SunPower provides two battery options: the SunVault Storage 13 with 12 kWh capacity and the SunVault Storage 26 with 24 kWh. The 26 model has one of the largest usable capacities of the batteries we reviewed and an above-average continuous power capacity of 6.8 kW.
Unfortunately, SunPower doesn’t disclose DoD information. Both batteries have a round-trip efficiency of 85%, the second-lowest in this review.
SunPower backs its solar batteries with a standard 10-year warranty. The SunVault Storage 13 battery has a 38 MWh throughput clause and a 4,000 cycle clause. The SunVault Storage 26 also has a 4,000 cycle clause but increases the throughput clause to 76 MWh. Both batteries are guaranteed a 70% end-of-warranty capacity.
SunVault systems are exclusive to SunPower solar panel systems. You can only get them through SunPower or its network of authorized dealers.
3.Tesla Powerwall 2
The Tesla Powerwall 2 is one of the most popular solar batteries. It’s an AC lithium-ion battery that can be retrofitted into any existing solar power system. It also has one of the best warranties of the batteries we reviewed, with a standard 10-year warranty and an unlimited cycle clause.
Pros and Cons
Here are the pros and cons of the Tesla Powerwall 2:
+ Can be retrofitted into existing solar systems
+ Guaranteed 70% capacity at the end of the warranty
+ Usable capacity of 13.5 kWh
– Can’t be purchased directly from Tesla
– Comes in only one size
Tesla Powerwall 2 Details
The Tesla Powerwall 2 offers a usable capacity of 13.5 kWh. It’s not modular — meaning it only comes in one size — but you can stack multiple batteries to meet your power needs. The battery has a continuous power rating of 5 kW, the industry standard. This measurement represents the amount of electricity that it can produce consistently.
The Powerwall 2 has a round-trip efficiency of 90%, meaning you can use 90% of the battery’s stored energy. The other 10% is lost during the energy storage process.
The Powerwall 2 has a depth of discharge (DoD) of 100%. This means they can be charged up to 100% of their usable capacity. Many manufacturers limit DoD because fully draining a battery of its capacity shortens its lifespan, but the Powerwall 2 can charge to its maximum capacity without affecting its lifespan.
The Powerwall 2 has a 10-year warranty with a guaranteed end-of-warranty capacity of 70%. It also has an unlimited cycle clause and no throughput clause, meaning the battery is covered for the entire term regardless of how many cycles it completes or how much energy it produces.
A cycle clause limits the number of times your battery can drain and recharge, called a charging cycle. This clause can end your warranty early if your battery completes its guaranteed cycles before the end of the term. A throughput clause measures the total potential energy generated in the battery’s lifetime. It can also end your warranty early if your battery reaches this threshold before the end of the term.
4.BYD Premium LVS & LVL
BYD is a huge Chinese battery manufacturer that recently launched into the global electric vehicle and energy storage markets. The company was first established back in 1995 and offers a wide variety of Lithium battery systems based on LFP (lithium iron phosphate) cells due to the increased safety, stability and lifespan compared to other lithium chemistries. BYD pioneered the modular tower battery concept, with the first generation stackable system launched back in 2017, and now boasts a range of modular batteries for high and low-voltage (48V) systems.
The LVS Premium series is a low-voltage (LV) 48V modular tower battery system designed to cater for different energy storage requirements. The LV tower system uses a battery monitoring unit (BMU) to manage and control each individual 4.0kWh module. Usable capacity is 100%, and up to 6 modules can be installed per tower for a total of 24kWh. For greater storage capacity, multiple towers of 4 modules can be linked together with a maximum of 16 towers, or 256kWh. Note, while the usable capacity is listed at 100%, the real-world capacity will be lower due to common inverter voltage limitations and inbuilt protection to prevent black-start events, which often occur when the battery is drained below 10% state of charge.
The BYD Premium LVL series has a much larger 15.4kWh capacity and is designed for larger off-grid, grid-tie and even off-grid energy storage applications. While not technically stackable, it is modular and scalable up to an impressive 983kWh, close to 1.0GWh.
5.Huawei LUNA2000
Huawei is not only a leader in communication and mobile technology but has become a leading innovator when it comes to solar energy storage technology. Building on decades of experience in large scale commercial and utility solar, Huawei moved into the residential solar market in 2018 with an efficient, lightweight hybrid solar inverter that offered an impressive range of features at a very competitive price. More recently, Huawei released the LUNA2000 modular residential battery system with an equally impressive range of features and new innovations as explained below.
The 5kWh LUNA2000 battery modules are built using lithium iron phosphate (LFP) cells and can be stacked three high for a maximum of 15kWh. However, the system can be expanded with a second stack offering up to 30kWh of total capacity with two stacks in parallel. Lithium Iron Phosphate (LFP) is widely known as one of the safest and most stable battery chemistries.
Unlike most other high-voltage battery systems, which are connected in series to increase the system voltage, the Huawei modules are connected in parallel as each module operates at 350V to 430V. This improves overall efficiency as each module is closer to the inverter optimum operating voltage and the current is reduced, resulting in lower cable and conversion losses. The LUNA2000 system also features several clever innovations, including a thermal management system that can pre-heat the cells in extremely low temperatures and an AI system that can detect short circuits or damage.
LUNA2000 battery unique innovations and features:
AI-powered internal cell short circuit diagnosis to avoid fire hazards
Module-level battery optimisers support new and old batteries in one system.
Internal heating system for better performance in extremely cold climates
6.Enphase IQ
Enphase is known for its high-quality inverters. Its solar battery, the Enphase IQ (formerly known as the Enphase Encharge), is integrated with this technology. The battery works with existing solar systems and provides software with insight into your power usage.
Pros and Cons
Here are the Enphase IQ’s key features:
+ Can connect to a gas-powered or solar generator
+ Includes two battery sizes for existing solar systems
+ Offers an optional five-year warranty extension
– Designed to work with systems with Enphase inverters
– Has a lower cycle clause than other batteries in our review
Enphase IQ Details
Enphase offers modular solar batteries in the following four models:
Enphase IQ 3: This battery has a capacity of 3.36 kWh and comes in a wide, heavy battery storage system.
Enphase IQ 3T: This model has the same capacity as the previous model but comes in a more compact design.
Enphase IQ 10: This battery has a usage capacity of 10.08 kWh but is heavy and bulky.
Enphase IQ 10T: This version of the 10.08 kWh battery is slightly slimmer and 24 pounds lighter.
You can customize your storage system by combining the 3/3T and 10/10T models. The 3/3T models have a continuous power rating of only 1.28 kW, and the 10/10T versions have 3.84 kW. All Enphase IQ models have a round-trip efficiency of 96% and a DoD of 100%. They’re LFP batteries, which are safer than Lithium Nickel Manganese Cobalt Oxide (NMC) models and have a longer lifespan.
All four batteries include a 10-year warranty and an industry-standard 4,000 cycle clause. These warranties include a throughput clause of 9.8 megawatt-hours (MWh) for the IQ 3 models and 29.4 MWh for the IQ 10 options. All four models have a guaranteed end-of-warranty capacity of 70%.
These batteries are made to work with Enphase inverters. Enphase IQ batteries are available through the Enphase sales team, online shop or solar panel installers.
7.PowerPlus Energy LiFe Premium
Based on direct experience and feedback from many professional off-grid designers and installers, the self-managed lithium batteries from Powerplus Energy in Melbourne, Australia, stood out as the best and most reliable choice for off-grid solar systems. Unlike the many common managed** lithium battery systems on the market from manufacturers such as BYD and LG, self-managed lithium battery systems do not require a communication connection (CAN bus) with the inverter and are compatible with almost all leading off-grid inverter-chargers. These batteries can also be used as a drop-in replacement for older lead-acid battery banks and generally do not shut down after a low-voltage or low SOC event. We should also note, in certain situations, self-managed battery modules can be ‘hot-swapped’ or replaced without shutting the down site if there is an issue.
The modular lithium batteries from Powerplus Energy feature high-performance lithium Ferro phosphate (LFP) cells which are widely known as the longest-lasting and most stable battery chemistry, backed by a 10-year warranty from a local, reputable manufacturer. Being Australian based with relatively low volumes, they are not yet widely available, however, production volume is increasing with the larger manufacturing facility now in operation. Powerplus Energy also offers a more affordable ECO 4kWh battery option.
8.Generac PWRcell
Overview
The Generac PWRcell is a modular, DC-coupled battery with one of the highest round-trip efficiencies on our list at 96.5%. It is an excellent option for new solar systems.
Pros and Cons
Here are the advantages and disadvantages of the Generac PWRcell:
+ Has one of the highest round-trip efficiencies of any battery on our list
+ Includes a protective battery cabinet for indoor or outdoor installation
+ Offers small modular battery options
– Contains cobalt, which is hard to recycle
– Is difficult to install on an existing solar power system
Generac PWRcell Details
The Generac PWRcell is one of the few modular DC-coupled batteries on our list. You’ll need to get a separate inverter, unlike AC-coupled batteries that include them. The Generac PWRcell uses NMC technology, the most common type of solar battery storage available. However, NMC batteries are difficult to recycle because they contain cobalt. They’re also more susceptible to fires when misused.
Generac customers can choose from four different system capacities. Each system is built with modules of 3 kWh.
PWRcell M3: This option includes three modules for a total of 9 kWh storage capacity and a continuous power rating of 3.4 kW.
PWRcell M4: This four-module system has a capacity of 12 kWh and a continuous power rating of 4.5 kW.
PWRcell M5: This five-module option stores 15 kWh with a 5.6 kW continuous power rating.
PWRcell M6: The largest six-module option has a continuous power rating of 6.7 kW and provides 18 kWh capacity.
The PWRcell battery has a round-trip efficiency of 96.5%. Its DoD is 84%, which is lower than many of the batteries on this list.
9.LG Chem RESU-10H
Overview
The LG Chem RESU-10H is a popular solar battery backed by one of the most respected electronics companies in the world. It works with existing solar systems and can be stacked for added storage options. The LG RESU-10H also has one of the highest round-trip capacities for an NMC battery at 94.5%.
Pros and Cons
We’ve listed the pros and cons of the LG Chem RESU-10H below:
+ Has one of the highest NMC round-trip efficiencies on our list
+ Is a great option for homeowners with lower energy needs
+ Is one of the most widely used solar batteries
– Guarantees a 60% end-of-warranty capacity, one of the lowest on our list
– Lower throughput clause could end the warranty early
LG Chem RESU-10H Details
The LG Chem RESU-10H is a good option for homes with lower energy needs. It has a usable capacity of 9.8 kWh, which is on the smaller end of the batteries we reviewed. Customers can add multiple batteries for increased storage capacity up to 32 kWh. The battery has a continuous power rating of 5 kW.
The LG Chem RESU-10H has a round-trip efficiency of 94.5%, one of the highest for NMC batteries we reviewed. It has a DoD of 90%.
LG Chem’s warranty is a little disappointing compared to other batteries. Though the company offers an industry-standard 10-year warranty, there’s a low throughput clause of 22.4 MWh. The battery has a 60% end-of-warranty capacity guarantee, which is standard but lower than other batteries on this list.
The LG Chem RESU-10H is available through LG’s network of licensed installers.
Battery sizing
Unfortunately, the one-size-fits-all approach is often taken when it comes to sizing a battery which can lead to poor performance and not meeting the consumer’s expectations. This is typically due to two main reasons:
Undersized batteries - do not have enough capacity to meet the household demand.
Oversized batteries - the solar array doesn’t have sufficient power to charge the battery, typically during the winter months.
To avoid these issues, a battery should be selected and sized by a qualified designer according to a number of important factors including; solar array size (existing or new), system type (on-grid or off-grid), backup power requirements, and most importantly, the evening or overnight energy consumption (kWh). Fortunately, most modern battery systems are modular and scalable so they can be sized accordingly.
Battery Capacity - kWh
Battery size or capacity is measured in kWh (kilowatt-hours). This is the total amount of energy a battery can store. However, the usable capacity may differ from the total battery capacity. Generally, the usable capacity is limited to 80 to 90% of the total battery capacity to increase the lifespan and avoid a potential battery shutdown at very low charge levels. For example, a lithium battery with 10kWh total capacity may have its usable capacity limited to 80% to increase its lifespan. Therefore, 8kWh of energy can be discharged on a daily basis. However, often the remaining 10 to 20% is available in emergencies, such as a prolonged blackout, depending on how the system is programmed.
Battery life and degradation
Home energy storage battery systems have only been widely available for around eight years, so real-world performance and degradation data is still incomplete. However, our data gathered so far through testing and monitoring of various (lithium) home battery systems suggests an 8 to 15+ year lifespan. The life of a battery is generally determined by either the number of charge and discharge cycles or total energy throughput (kWh). All batteries lose capacity over time with the end-of-life generally after a lithium battery has lost around 30% of its original capacity; this generally occurs after 10 years, based on one full charge cycle per day.
What is solar panel battery storage?
An energy-storage system, also called a home or solar battery, lets you capture electricity so you can use it at another time. For example, you can store the electricity your solar panels generate during the day and use it at night.
This relatively new technology may be worth considering if you generate your own energy at home with solar panels but could use more of it outside daylight hours – or plan to start doing so.
Is solar battery storage right for my home?
If you have solar PV panels, or are planning to install them, then using home batteries to store electricity you’ve generated will help you to maximise the amount of renewable energy you use. In fact, 60% of people who have, or would consider, a home battery told us the reason was so they could use more of the electricity generated by their solar panels.*
Home-energy storage will also reduce the electricity you use from the grid, and cut your energy bills. If your home is off-grid, it can help to reduce your use of fossil fuel back-up generators.
Even without solar panels, you may be looking to make use of time-of-use tariffs with a battery. These let you store up electricity while it’s cheap (overnight, for example) so you can use it during peak times.
A few energy companies have launched these already, and we expect to see more of them as they can help to balance energy supply and demand, and reduce the need for additional fossil-fuel generation at peak times.
If, for example, it's a windy night and lots of wind turbines are generating electricity for the grid that no-one is using, it makes sense to make the most of that with battery storage.
If you’re at home during the day and already use a large proportion of the electricity you generate through solar panels, or divert surplus electricity to heat your water (for example), then a battery may not be right for you.
What size solar storage battery do I need?
The average home uses around 8kWh of electricity per day. The capacity of new lithium-ion batteries ranges from around 1kWh up to as much as 15kWh.
Ideally, you want a battery that will cover your evening and night-time electricity usage, ready to be charged up again when the sun comes up. You'll also need to bear in mind how much your solar panels can generate, as there's no point buying a battery that's bigger than they can fill.
With a battery that is well chosen for your home's energy use and your solar panels' output, you should find that you can have enough electricity to serve your evening needs for most of the year. You might find that you are still drawing on grid electricity for some of the longest winter nights.
Types of Solar Batteries
Solar batteries are differentiated by their chemical composition. Lead-acid and lithium-ion batteries are the two most popular types.
Lead-acid Batteries
Lead-acid batteries have been around for many years. They take longer to charge and have a shorter lifespan than lithium-ion options. They’re also bulkier and heavier. Lead-acid batteries have become more popular for off-grid systems than residential installations.
Lithium Batteries
Lithium-ion varieties are the most common type of solar battery, with Lithium Nickel Manganese Cobalt Oxide (NMC) and Lithium Iron Phosphate (LFP) being the most popular. NMC batteries have older technology but are more widely used. They provide ample power but are smaller in size. NMC batteries also contain cobalt, which makes them hard to recycle.
LFP batteries are eco-friendly. They have new technology that provides a longer lifespan and better efficiency than NMC varieties.
How To Choose the Best Solar Battery
You’ll need to consider several factors to find the best solar battery for your system.
Battery Capacity
Battery capacity is measured in kilowatt-hours (kWh) and indicates the amount of energy that can be stored at once. Usable capacity measures the amount of energy that can be used from the battery. This measurement is lower than the actual battery capacity because a portion of the stored energy is used to run the battery.
Battery capacity should match your solar power production. Batteries that are too big won’t use their full capacity, while undersized batteries won’t keep up with the amount of energy your system produces. Look for batteries with a capacity of 10 kWh, enough for most homeowners’ energy needs.
Coupling Options
Solar systems generate direct current (DC) electricity that must be converted to alternating current (AC) electricity for your home’s appliances. In an AC-coupled system, the energy is converted to AC electricity at the inverter, converted back to DC to be stored in the battery, and then converted to AC for use in your home. In a DC-coupled system, energy is converted only once.
AC-coupled batteries work best as add-ons to existing solar power systems. However, they’re less efficient than their DC counterparts because some energy is lost in each conversion.
DC-coupled batteries are better for new solar installations. They’re more efficient and can be charged by your solar panels when the grid system is down. However, they’re complicated to install and could increase installation costs.
AC coupling has been used more commonly in residential systems, but DC coupling is becoming more popular as more options become available.
Also read:Top 10 Lithium Battery Manufacturers in USA, 2022
Depth of Discharge
Depth of discharge (DoD) refers to the percentage of the battery discharged relative to its overall capacity. This affects lifespan: Regularly discharging a battery at a lower percentage will yield more useful cycles than frequently draining the battery to its maximum DoD.
Many battery manufacturers limit DoD to ensure the battery will perform long-term. The industry standard is 80% to 100% for lithium-ion batteries and 50% for lead-acid options.
Power Rating
Power ratings indicate the amount of electricity that can be produced in a specific time frame. These ratings are measured in kW or amps and broken into two categories:
Continuous power: This indicates how much power can be produced over time.
Peak power: This is the maximum amount of power that can be produced instantly.
Battery capacity and power ratings shed insight on solar batteries’ power potential. High-capacity batteries with low power ratings can run smaller appliances for longer. Low-capacity batteries with high power ratings offer more powerful bursts of energy but drain quicker.
Battery storage installation systems
There are two types of battery installation: DC and AC systems.
DC battery systems
A DC system is connected directly to the generation source (eg. solar panels), before the electricity generation meter. You won’t need another inverter, which is more efficient.
However, charging and discharging is less efficient, so could affect your feed-in tariff. DC systems aren't usually recommended if you’re retrofitting a battery to an existing PV system.
DC systems can’t be charged from the grid, according to the Energy Saving Trust.
AC battery systems
These are connected after the electricity generation meter. So you’ll need an AC/DC power unit to convert the electricity you generate into AC you can use in your home (and back again to store it in your battery).
AC systems are more expensive than DC systems, according to the Energy Saving Trust. But an AC system won’t affect your FITs payments, as the generation meter can register the total system output.
Solar panel battery storage: pros and cons
Pros
Helps you use more of the electricity you generate.
Some firms pay you for allowing your battery to be used to store excess grid electricity.
Could enable you to take advantage of cheap-rate electricity.
Require little maintenance: ‘Fit and forget’, said one owner.
Cons
Currently pricey, so payback time may be long.
A DC system could reduce your FIT payments.
Likely to need replacing during the lifetime of a solar PV system.
If retro-fitted to existing solar PV, you may need a new inverter.
Batteries added to existing solar PV systems are subject to 20% VAT. Batteries installed at the same time as solar panels are subject to 0% VAT until 2027.
How We Reviewed Solar Cell RankingsWe spent hundreds of hours researching solar batteries, analyzing cycle efficiency, performance, product longevity, warranty and usable capacity data. We compared each metric to industry standards.
We analyzed customer reviews to gauge each battery’s performance and contacted customer service to understand the buying and installation process. We also assessed each manufacturer’s reputation, dependability and contributions to the solar industry.
How long can solar batteries last?
Residential solar batteries can last 5 to 15 years, with lithium-ion batteries lasting the longest. Solar panel systems typically last 20 to 30 years, so you’ll need to replace your solar battery from time to time.
Which solar battery lasts the longest?
Lithium-ion solar batteries last the longest. They have the best storage capacity and record the highest depth of discharge levels. They cost more than other types, such as lead-acid batteries, but you’ll need to replace them less frequently.
How long does a 10 kW solar battery last?
The average home uses 750 to 1,000 watts of energy per hour, so a 10 kW solar battery can last about 10 to 12 hours without recharging. This is enough energy to run your refrigerator and several small appliances during a power outage. However, a high-power system such as an air conditioner will drain the battery quicker.
What is the best solar battery for solar panels?
Lead-acid and lithium-ion are the two most popular types of solar batteries. Lithium-ion batteries are the best option due to their longer lifespan and larger solar energy storage capacity. However, lead-acid and saltwater batteries are more affordable.
Which battery is best for solar?
Lithium-ion batteries
Lead-acid and lithium-ion are the two most popular types of solar batteries. Lithium-ion batteries are the best option due to their longer lifespan and larger solar energy storage capacity. However, lead-acid and saltwater batteries are more affordable.
Is it worth getting a battery for my solar system?
Are solar backup batteries worth it in the long run? Absolutely. From supplying your home with power during an outrage to helping minimize the amount of electricity to pull from the power grid, a battery is a practical and beneficial addition to any home solar system.
How long will a 10kw solar battery last?
But if your plan is to keep the essentials–phones, computers, WiFi, refrigerator and some lights–running during an outage, you can expect a 10 kWh battery will keep those things running for nearly 24 full hours.
How much is a 5kW solar battery?
A battery system for a 5kW solar unit costs generally between $1,300 to $2,000 per kWh. So for a 5kW system you might be looking at a total for the battery storage of around $7,000 to $10,000. The average time (industry wide) it takes to recover that initial outlay through reduced power costs is now below 10 years.