Expert review of sonnen batteries | costs, performance, warranties

German battery manufacturer sonnen opened its doors in 2010 and quickly became the breakout star of the German energy storage market with its cutting-edge battery solutions. 

The company’s hometown success led to its expansion into the U.S. market in 2015. Since then, sonnen has become synonymous with reliable energy storage and is a popular brand from the U.S. all the way to Australia.

The current batteries from sonnen are a great option for most homeowners interested in battery storage, especially if they want a battery they can use daily. Let’s look at what sonnen batteries offer, from features to price, and how they stack up to other popular batteries.

Expert review of sonnen batteries

There’s a reason sonnen has been in the storage market for over a decade - the company makes good-quality batteries that will meet the needs of most homeowners. sonnen batteries are best for suburban homeowners interested in backup power for key appliances like refrigerators, those who want to avoid expensive peak electric rates, or those who don’t have access to net metering.

What sets sonnen apart? It's not just about the quality; it's about longevity. With an impressive 10-year, 10,000-cycle warranty, sonnen's commitment to durability is unmatched. The confidence in their product is further bolstered by the company's reputation and financial performance, assuring homeowners that they'll be there to honor every warranty promise.

While sonnen might not be the ideal fit for those aiming to power an entire household off-grid or energy-intensive appliances like air conditioners, it’s a solid solution for the majority of homeowners. The capacity and power packed into a sonnen battery are sufficient to navigate expensive time-of-use rates and keep crucial appliances running during power outages.

sonnenCore+ overview

The sonnenCore+ is a dependable, everyday battery solution that caters to the practical needs of most homeowners. There are two sonnenCore+ models: the 10 kWh sonnenCore+ 10, and the larger 20 kWh sonnenCore+ 20.

The sonnenCore+ houses individual lithium-iron-phosphate battery packs, energy management equipment, and an inverter within an indoor-rated cabinet. The sonnenCore+ 10 comprises two battery modules, while the larger sonnenCore+ 20 accommodates four. The all-in-one design makes for easy installation and a sleek design. 

Designed with homeowner needs in mind, the sonnenCore+ offers three operating modes – Time-of-use, Solar self-consumption, and Emergency backup power. This adaptability allows users to optimize energy usage, maximize solar consumption, and ensure reliable backup power during unforeseen outages.

For those looking for more power and capacity, the sonnenCore+ models are stackable, allowing you to reach a whopping 60 kWh of capacity and 14.4 kW of output. A maximum of three units can be stacked together.

The following table outlines key performance specifications of the sonnenCore+ 10 and sonnenCore+ 20 models:  

Model	sonnenCore+
Capacity	10 - 20 kWh
Nominal power rating	4.8 kW
Round-trip efficiency	85.8%
Chemistry	LFP
Warranty	10 years or 10,000 cycles
Expandable?	Yes, up to 60 kWh
Indoor or outdoor rated?	Indoor rated

sonnenEvo overview

The sonnenEvo uses the same technology as the sonnenCore+ models, with identical operating modes, providing the same warranty coverage, and is conveniently stackable.

Where they differ is the cabinet in which the battery modules are stored. The sonnenEvo cabinet is outdoor rated, making them a great choice for homeowners who don’t have the indoor space for a sonnenCore+. The sonnenEvo comes in a single size, offering a 10 kWh unit in a more compact cabinet.

Up to three sonnenEvo units can be installed together, reaching 30 kWh of storage capacity and 14.4 kW of output. The following table breaks down important features of a single sonnenEvo unit.

Model	sonnenEvo
Usable capacity	10 kWh
Nominal power rating	4.8 kW
Round-trip efficiency	85.8%
Chemistry	LFP
Warranty	10 years or 10,000 cycles
Expandable?	Yes, up to 30 kWh
Indoor or outdoor rated?	Indoor and outdoor-rated

How much does a sonnen battery cost? 

You can expect a single 10 kWh sonnen battery installation to cost between $12,000 and $16,000, depending on your chosen installation company. sonnen battery prices fall within the average cost of a solar battery installation. It’s important to note that opting for the larger sonnenCore+20 or installing more than one unit will increase the total price of a sonnen energy storage system. 

Considering the overall cost, sonnen's hardware might appear slightly pricier per kWh compared to some competitors. However, the modular design of sonnen batteries requires smaller crews for installation, translating to lower labor costs. 

The upfront cost of energy storage can be daunting, but there are battery incentives and rebates available that can lower the price. Solar batteries like those sold by sonnen are eligible for the 30% federal tax credit, saving homeowners thousands of dollars on their income taxes. Also, sonnen batteries are eligible for many virtual power plant programs, where utilities pay homeowners in exchange for access to their stored power, leading to a quicker payback period. 

Pros and cons of sonnen’s home batteries

Pros of sonnen batteries	Cons of sonnen batteries
Excellent warranty	Lower efficiency than competitors
Stackable	Low power output
VPP capabilities	Sizing is not as customizable as some competitors
LFP chemistry	Availability

Advantages of sonnen solar batteries

• Excellent warranty. Sonnen offers a best-in-class warranty that guarantees 70% capacity retention after the first of 10 years or 10,000 cycles. 10,000 cycles is a lot, so you’re likely to be covered for a full 10 years, making this a great battery for those looking to use their storage system daily. 

• Stackable. As a stackable battery, you can install up to three units and increase your storage capacity and power output. 

• Virtual Power Plant capabilities. Sonenn has been an early participant in VPP programs that allow utilities to pay homeowners for access to their home batteries. Its batteries are designed to be VPP compatible, so they can ease the stress on the grid and earn battery owners extra cash, shortening their payback period. 

• LFP chemistry. Sonnen uses lithium-iron phosphate batteries, which can withstand high temperatures better than other lithium battery technologies, have a longer lifespan, and

Disadvantages of sonnen solar batteries 

• Lower power output than competitors. One sonnenCore+ or sonnenEvo unit has a continuous power output of 4.8 kW, which is lower than that of other batteries on the market, especially for the sonnenCore+ 20 model. It will still provide enough power for most homeowners but won’t be ideal for those looking to run powerful appliances like an air conditioner or sewer pump. 

• Lower efficiency than competitors. Today's most popular AC solar batteries typically have a round-trip efficiency of around 89%. sonnen’s batteries come in closer to 86%. This won’t make too much of a difference in the day-to-day operation of the battery.

• Sizing is not as customizable as competitors. While the sonnenCore and sonnenEvo are modular and stackable, they don’t offer the same size customization as others. For example, the Panasonic EverVolt and Enphase IQ battery systems allow you to add 5 kWh or 3 kWh of storage to your unit for the correct size. Sonnen only expands in increments of 10 kWh. 

• Availability. According to the SolarReviews’ 2024 Solar Industry Survey, less than 9% of respondents carried sonnen batteries, so it may be harder to come by an installer with sonnen batteries in stock. For reference, Enphase’s batteries were carried by over 50% of respondents. 

Sonnen batteries vs. Tesla Powerwall

	sonnenCore+ 10	Tesla Powerwall 2
Usable capacity	10 kWh	13.5 kWh
Continuous power output	4.8 kW	5 kW
Est. installation cost	$12,000 - $16,000	$11,000 - $15,000
Chemistry	LFP	NMC
Warranty	10 years, 10,000 cycles	10 years, minimum 2,800 cycles

Overall, sonnen’s batteries are very similar to the Tesla Powerwall, and both make a great choice for homeowners looking for storage. The right one for you will depend on your specific energy needs. 

The biggest strength of sonnen batteries is their long-lasting warranty. Your sonnen battery will likely be covered for the full ten years, as you probably won’t cycle your battery 10,000 times before a decade is up. The high cycle life makes sonnen a great option for a battery that is getting daily use. You can thank the LFP batteries for sonnen’s extended lifespan, and because they don’t contain toxic cobalt, they’re safer and less susceptible to overheating than the Powerwall.

The Powerwall, however, is a bit more powerful and stores more energy than the sonnenCore+ 10. So if your electric usage is higher but not so high that you need to size up to the 20 kWh sonnenCore+, the Powerwall can be a happy medium.

Also, the Powerwall costs less for the amount of storage you get. Plus, if you're already part of the Tesla ecosystem with an electric vehicle, the convenient integration of the Powerwall with the same app as your car is an added bonus. 

The Powerwall does have an unlimited cycle warranty, but only if the battery is operated under a certain combination of operating modes. If you use Tesla operating modes that are outside of the ones listed in the warranty, the cycle life drops to 2,800 cycles. 

Finding the right installer for solar battery storage with SolarReviews

The sonnenCore+ and sonnenEvo are great batteries from a reliable manufacturer. But, the most important part of any renewable energy project is the installation company. Solar batteries are a 10+ year investment, and you need to find an installer you trust to support you every step of the way. 

SolarReviews is here to ensure you have the right partners every step of the way for your clean energy journey. Because when it comes to solar batteries, the right installer makes all the difference.

We partner with reliable, local solar installers who are experts in solar and battery storage in your area. These installers guide you through the process, providing invaluable insights to make informed decisions about the right solar battery brand and size, ensuring a top-notch installation.

Using our solar storage calculator, you can estimate what energy storage costs are near you and get quotes from multiple solar companies to get the best installation and price possible. 

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