How do solar batteries compare? Tesla Powerwall vs. Sonnen batterie vs. Aquion vs. LG Chem RESU

Reading Time: 6 minutes

compare solar battery companies Tesla Sonnen LG Aquion

Home energy storage is a relatively new technology that’s steadily gained interest over the past few years, and it’s hard to know where to start when comparing all your options. Top solar batteries like those made by Tesla and Sonnen make it possible for homeowners and businesses to store their excess solar energy instead of sending it back to the grid, so that when the power goes out or electricity rates spike they can keep the lights on. If you want to install a solar battery at your home, you have a few different choices currently available to you. Compare the Tesla Powerwall vs. Sonnen eco vs. LG Chem vs. Aquion Aspen in terms of capacity, warranty, and price.

Tesla Powerwall: Elon Musk’s solution for home solar batteries

tesla powerwall batteryCapacity: 13.5 kilowatt-hours (kWh)
List price (before installation): $5,500
Warranty: 10 years

The Tesla Powerwall is an energy storage industry leader for a few reasons. First and foremost, the Powerwall is the battery that brought energy storage into the mainstream for many homeowners. Tesla, already well known for its innovative electric cars, announced the first-generation Powerwall in 2015, and overhauled the “Powerwall 2.0” in 2016. The Powerwall is a lithium ion battery with a similar chemistry to the batteries used in Tesla vehicles. It is designed for integration with a solar panel system, but can also be used solely for home backup power.

The second-generation Tesla Powerwall also offers one of the best ratios of cost to capacity of any product available in the United States. One Powerwall can store 13.5 kWh – enough to power essential appliances for a full 24 hours – and comes with an integrated inverter. Before installation, the Powerwall costs $5,500, and Tesla estimates that installation costs and associated equipment will bring the all-in cost to approximately $7,000.

The Powerwall comes with a 10-year warranty that assumes your battery is used for daily charging and draining. However, unlike some other battery manufacturers, Tesla does not currently offer any coverage related to the battery’s performance, or how much storage capacity the battery will lose during that time.

For more on the Powerwall, read EnergySage’s complete Tesla Powerwall review.

solar batteries cta

Sonnen eco: Germany’s leading battery producer takes on the U.S.

Sonnen eco compact batteryCapacity: starts at 4 kilowatt-hours (kWh)
List price (before installation): $9,950 (for a 4 kWh model)
Warranty: 10 years, 70% capacity

The Sonnen eco is a 4 kWh+ home battery manufactured by sonnenBatterie, an energy storage company based in Germany. The eco has been available in the U.S. since 2017 through the company’s installer network.

Like the Tesla Powerwall, the eco is a lithium ion battery that is designed for integration with a solar panel system. It also comes with an integrated inverter. One of the main ways that Sonnen distinguishes the eco from other solar batteries on the market is through its self-learning software, which can help homes with solar panel systems connected to the grid increase their solar self-consumption and manage time-of-use electricity rates.

The eco has a smaller storage capacity than the Tesla Powerwall (4 kWh vs. 13.5 kWh). On the plus side, Sonnen also offers a minimum guaranteed capacity as part of its warranty while Tesla does not – over the course of the 10-year warranty, the eco compact will maintain at least 70 percent of its storage capacity. As mentioned earlier, Tesla offers no such warranty.

For more on the eco compact, read EnergySage’s complete Sonnen eco review.

Aquion Aspen: innovative saltwater battery technology

Aquion saltwater home batteryCapacity: 2.2 kWh
List price (before installation): ~$1,000
Warranty: 8 years, 70% capacity

(Note: Aquion filed for Chapter 11 bankruptcy in 2017 and stopped manufacture and marketing of its products. They have since emerged, but may not re-enter the residential market.)

The Aquion Aspen is distinct from other small-scale solar batteries on the market for a few reasons. The first is its size: one Aspen is 2.2 kWh, approximately one-sixth of the capacity of one Powerwall. It comes with a list price to match: a single Aquion battery costs approximately $1,000 (or about one-sixth the cost). These smaller batteries can also be “stacked” – if you want more storage capacity at your home, you can purchase and connect multiple Aquion batteries together to create a larger storage system.

Perhaps the biggest difference, however, is in the Aspen battery’s chemistry. Unlike the Powerwall and eco compact, Aquion’s batteries use saltwater technology. For many homeowners, the most important distinction between battery chemistries is in their environmental impact. Lithium ion batteries must be carefully recycled at the end of their useful life because the chemicals used in their composition can be hazardous if not treated properly. By comparison, Aquion batteries use a saltwater electrolyte chemistry that is environmentally benign. In fact, Aspen batteries are Cradle to Cradle Certified.

Like Sonnen and unlike Tesla, Aquion also offers a minimum guaranteed capacity as part of its warranty – over the course of the 8-year warranty, the Aspen will maintain at least 70 percent of its storage capacity.

LG Chem RESU: home energy storage from a leading electronics maker

LG RESU home solar batteryCapacity: 3.3-9.8 kWh
Listed price (before installation): ~$6,000 – $7,000
Warranty: 10 years, 60% capacity

Another major player in the worldwide energy storage market is leading electronics manufacturer LG, based in South Korea. Their RESU battery is one of the more popular options for solar-plus-storage systems in Australia and Europe.

The RESU is a lithium ion battery and comes in three different sizes: 3.3 kWh, 6.5 kWh and 10 kWh. It comes with a 10-year warranty that offers a minimum guaranteed capacity of 60 percent. Because the RESU is relatively new to the U.S. market, the equipment cost isn’t yet known, but early indicators suggest that it is priced at between $6,000 and $7,000 (without inverter costs or installation).

For more on the RESU, read EnergySage’s complete LG Chem RESU review.


Panasonic, Nissan, BMW: major companies entering the industry

Tesla, Sonnen and Aquion make three of the most popular batteries currently available in the United States, but the market is becoming much more competitive. Panasonic, Nissan, BMW, and Mercedes-Benz have all announced their intention to enter the fray with their own energy storage technologies in the next few years. Nissan and BMW are both manufacturing home storage systems with used electric car batteries, while Mercedes-Benz is has launched a standalone energy storage system (and has a former Sonnen executive leading the project). (NOTE: You can read EnergySage’s Mercedes home battery review here.)

Where to buy solar batteries for your home

If you want to install a home battery pack, you will most likely need to work through a certified installer. Adding energy storage technology to your home is a complicated process that requires electrical expertise, certifications, and knowledge of the best practices required to install a solar-plus-storage system correctly.

A qualified EnergySage-approved company can give you the best recommendation about the energy storage options available to homeowners today. If you are interested in receiving competing installation quotes for solar and energy storage options from local installers near you, simply join the EnergySage Solar Marketplace today and indicate what products you’re interested in when filling out your profile’s preferences section.

solar batteries cta

10 thoughts on “How do solar batteries compare? Tesla Powerwall vs. Sonnen batterie vs. Aquion vs. LG Chem RESU

  1. Dan


    That’s will be one of its main uses, OFF-GRID. If you think you are going to purchase a battery pack so you can run your house for only 24hs and then pray: a – you have solar panels and b- there is sun out there so panels can recharge the powerwalll… it is not going to work.

    Once 10kWh drops below $1500, you will see homeowners purchasing it in populated areas. In the meantime, as a home owner in Colorado, perfect state for solar panels, I’m looking at the following:
    1- Monthly electric bill $100 – with another $100 for gas.
    2- Powerball – $6000 + a 6kwh solar panel set up: $8000 = $14 000
    It would take me 13 years of $100/month to recoup such money.

  2. Karissa

    Just a note about actual facts of the batteries: the Sonnen Batteries are Lithium IRON, this is different than Lithium ION and should be noted when making facts about the battery.

  3. Perry

    Cost of new solar system in Phoenix area is being quoted to around 2.5$ per watt is it cheaper in other states

  4. Barry Brandt

    Note: most of these batteries are designed for daily discharge use only.
    They are designed to fully discharge each day.
    They will not recharge in the event of a power failure lasting more than one day.
    The Solar inverter will not come on the next day due to inadequate sine wave minimum requirements.
    They will Not work in an “Off Grid” situation

  5. PD

    The following are notes for California pertaining to the LG Chem.
    It can be programmed for more than just daily discharge use.
    The battery can also be programmed to discharge during “peak” hours to combat Time of Use plans.
    Also, unlike before, LG will recharge while the sun is out during an outage.

Leave a Reply

Your email address will not be published. Required fields are marked *