To gain true energy freedom and autonomy, you have to get a battery bank for your solar system. Choosing one isn’t easy, especially since the energy storage system can account for more than 50% of the PV system’s total costs. That’s why we’ll be looking at the best solar batteries in this article to help you separate the wheat from the chaff and save money.
Key takeaways
Lithium-ion batteries in the US are eligible for Solar Tax Credit!
Solar batteries store excess solar energy produced by solar panels during the day. You can use it at night when the sun isn't shining, during power outages or at the hours of peak electricity demand to save money.
The decision of whether or not to add energy storage is not to be taken lightly because of the high solar battery cost. A simple grid-tie system without batteries provides better ROI than an off-grid installation or even a hybrid one in some cases, depending on your utility rates. However, for homeowners in areas with frequent power outages, solar batteries are a smart investment. They become essential if you go for complete energy independence.
The number of batteries needed for your home depends on your energy consumption and why you need them. The optimal size of a battery bank is going to be different in off-grid and hybrid systems. Some batteries have modular design: you can add battery modules to a cabinet and the energy capacity of the unit will increase if you need a larger bank.
DC and AC batteries differ in how you add them to your system. DC-battery systems are less confusing but AC-systems are surprisingly easier to implement.
Solar panels produce direct current by themselves and they can directly charge a DC battery. There always should be a charge controller in between to make the voltage from panels safe for the battery. The DC from the battery and panels then goes to an inverter, turns into AC and flows into the grid or to the appliances.
A DC-coupled system is a low-cost setup for mobile installations and residential systems under 6-7 kW in size. However, it’s not always possible to add a DC battery to an existing system – consult with your installer when in doubt.
Standard grid-tie inverters cannot be paired with DC batteries. You need a hybrid or an off-grid inverter to pair it with DC energy storage.
AC batteries, on the other hand, require a separate inverter that is connected to your electric panel. The inverter draws AC from the grid, converts it to DC and sends it to the battery. When extras are needed, it draws energy from the battery, converts it back to AC and sends it elsewhere. The most notable examples are Tesla Powerwall 2 and Enphase Encharge.
Multiple conversions mean energy losses and this makes AC battery system less efficient. Besides, an extra inverter makes it more expensive. However, an AC battery is much easier to add to an existing system even if you have a grid-tie inverter. AC-coupled systems are a better option for large houses, heavy loads and EV charging. Read more in our article on AC and DC energy storage systems.
For a long time, lead-acid batteries were the most popular type of energy storage. They are still widely used because these are the cheapest batteries for solar systems. The downside is how vulnerable they are. Overheating, extreme cold, overcharging, deep discharge — all of these things shorten the lifespan of a lead-acid battery drastically. A lead-acid battery can be safely discharged only by 50% which means that only half of its capacity is actually usable.
Lead acid batteries
There are three most common subtypes of lead-acid batteries that are used in solar systems:
With all the downsides of lead-acid energy storage, it’s not a surprise that lithium batteries take over the market. Their efficiency is higher: 85-95% compared to 60-80% of lead-acid ones. They last longer: most come with warranties for 10 years. Their acceptable depth of discharge (DOD) rate reaches 100%. They charge faster, they are lighter and take up less space. The only downside is their higher price but the specs make them worth it.
There are three most common types of lithium batteries that are used in PV systems:
Let's summarize all information that we've learned in a table – this way, the pros and cons of each type will be easier to see:
Let’s look at a few batteries that can be used at home in combination with solar panels. We based the rankings in this article on expert opinions, customer reviews and technical details of the products. Some of these models we offer at A1 SolarStore!
Solar systems may appear complicated. First, you have to choose all these different elements and make sure they match. Then, the installation starts and it also can be stressful and time-consuming. Here is the good news: a system made of AC solar panels is much simpler. Well, is there any bad news? What are these ACpanels anyway? Let's find out.
SolarEdge 10 kWh Home Battery SE-BAT-10K1PS0B-02
Pickup on Fri, Feb 07 from West Boylston, MA
Delivery on Feb 12–18
The SolarEdge Home Battery BAT-10K1P is a high-efficiency energy storage solution designed to work seamlessly with SolarEdge Home Hub Inverters. With a 9.7 kWh usable capacity and 94.5% roundtrip efficiency, it allows homeowners to store more energy for use during peak hours or power outages. The battery provides 5,000W continuous power and up to 7,500W peak output, making it a reliable source for backup power. Its 100% depth of discharge ensures maximum utilization of stored energy.
Built for flexibility, the battery can be installed indoors or outdoors, either wall-mounted or floor-mounted. It features wireless communication through the SolarEdge Home Network, simplifying setup and reducing installation costs. Safety is a priority, with UL-certified protection standards, Rapid Shutdown, and SafeDC™ technology to prevent electrical hazards. With a 10-year warranty, this battery is an excellent long-term investment for homeowners looking to optimize their solar energy use and ensure reliable backup power.
Pickup on Fri, Feb 07 from Millstone, NJ
Delivery on Feb 12–18
The Enphase IQ Battery 5P is a reliable and efficient energy storage solution designed for homes with solar power. It has a 5.0 kWh usable capacity and uses six built-in microinverters to provide a steady 3.84 kVA continuous power output rating with peaks of up to 7.68 kVA. The battery is designed for backup power, self-consumption, and time-of-use optimization, allowing homeowners to store excess solar energy and use it when needed. With wired communication for a stable connection and the ability to update software remotely, it ensures seamless integration with Enphase solar systems.
Built for durability, the IQ Battery 5P features lithium iron phosphate (LFP) chemistry, known for its safety and longevity. It has natural convection cooling, eliminating the need for fans or moving parts, and operates in a wide temperature range from -4°F to 131°F. The 15-year limited warranty ensures long-term reliability, while the NEMA 3R-rated enclosure makes it suitable for both indoor and outdoor installations. With remote monitoring via the Enphase App, homeowners can easily track their energy usage and system performance.
Fortress Power Evault Max 18.5 kWh Lithium Battery Storage
Pickup on Fri, Feb 07 from Las Vegas, NV
Delivery on Feb 12–18
The Fortress Power eVault Max 18.5 kWh is a high-capacity Lithium Iron Phosphate (LiFePO4) battery designed for residential and commercial energy storage. It provides a scalable solution, allowing users to expand their system up to 370 kWh for larger energy needs. This battery is compatible with AC and DC solar systems, making it a great choice for off-grid setups, backup power, and peak charge reduction. The intelligent Battery Management System (BMS) ensures safe operation, efficient energy use, and real-time monitoring through a built-in touchscreen LCD display.
With an impressive 98% round-trip efficiency, the eVault Max 18.5 delivers reliable power while maintaining a long lifespan. It operates in extreme temperatures, with a durable aluminum enclosure (IP55-rated) for indoor and outdoor installations. Safety is a priority, with certifications including UL1642, UL1973, and UL9540. Weighing 520 lbs, this unit is one of the largest single residential batteries on the market, providing steady power output for both daily energy use and emergency backup.
Briggs & Stratton (SimpliPHI) 4.9 Battery 4.98 kWh Wall Mountable
Pickup on Fri, Feb 07 from Oxnard, CA
Delivery on Feb 12–18
The SimpliPHI Battery is a powerful 4.98 kWh energy storage solution that uses advanced Lithium Ferro Phosphate (LFP) technology. It's a versatile battery that can work with all major inverters, making it perfect for both new installations and upgrades to existing systems. What makes it particularly appealing is its impressive 15-year warranty and ability to work in various weather conditions, whether installed indoors or outdoors.
The battery is built with both safety and performance in mind. It achieves 96% round-trip efficiency and can handle over 10,000 charging cycles when used at 80% depth of discharge. It's also maintenance-free, requiring no special ventilation or cooling systems, and includes built-in protection features to prevent overcharging and discharging. For larger energy needs, the system is scalable - you can connect up to 60 batteries together to create a substantial 299 kWh storage system. Briggs & Stratton is a company with a long history and a strong reputation.
MK Battery Deka 5.3kWh 100Ah 48V Lithium Iron Phospate Battery DD5300
Pickup on Fri, Feb 07 from Sacramento, CA
Delivery on Feb 12–18
The Deka Duration DD5300 is a versatile lithium iron phosphate (LFP) battery system that can work with both low and high voltage setups. The base model offers 5.3 kWh of storage capacity and can be expanded significantly - up to 212 kWh for low voltage systems or an impressive 763.2 kWh for high voltage applications. This makes it suitable for a wide range of uses, from residential backup power to larger commercial installations.
Built for longevity, the DD5300 comes with a 15-year design life and can handle up to 7,000 charging cycles while maintaining at least 80% of its capacity. The system is quite adaptable to different environments, operating in temperatures from -4°F to 131°F, and includes advanced features like real-time balancing and adaptive charging logic. It can be monitored and controlled through a mobile app, making it user-friendly for everyday management.
The lifespan of solar batteries depends on type and brand, as well as on how you treat it. A lithium-ion battery lasts between 10 to 15 years on average while the lifespan of a lead-acid battery ranges from 2 to 8 years.
To prolong the lifespan of a solar battery and your equipment, it is essential to maintain it properly. Keep it away from extreme cold or high temperatures. Always add a charge controller in between the panels and the battery. It protects your energy storage from the high voltage of solar array and prevents overcharging and deep discharge. Using a battery management system can help optimize the battery's performance and increase its lifespan.
10 tips for maintaining your solar battery system
Find your best solar batteries
Keep the sun on 24/7 with a reliable energy storage bank. Don’t let power outages change your plans!
SHOP SOLAR BATTERIES
Writing for electronics manufacturers like Bitmain taught Maxim to extract the important details from lengthy equipment documentation. At the same time, it made him aware of the environmental effects, and he put his talents to work for a renewable future.
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