Panasonic Evervolt Home Battery Review: A Modular and Powerful Approach

6.8

Panasonic Evervolt Home Battery

Like

• Modular design
• Good warranty
• Well-rounded performance and efficiency
• Can be installed without solar panels

Don't like

• Lower depth of discharge
• Lack of customer support options

Installing a solar battery with your solar panels can help you keep things running when the power goes out. But finding the right solar battery for your home can be tricky. If you're looking for power and flexibility, Panasonic's new home battery might be worth looking into.

The Evervolt system combines a modular battery design with a powerful hybrid inverter. Energy needs vary from house to house, making finding the right battery for your specific needs a challenge. One of the best things the Evervolt has going for it is flexibility for a variety of energy needs and uses. 

"Everybody's needs are different. Some of the houses are big, some are small. Some want more power for air conditioning or running other heavier loads. So we have flexibility for whatever they can get or want, and load management capacity," Mukesh Sethi, director of solar and energy storage at Panasonic, told CNET.

We did not conduct any hands-on testing for this review. Solar batteries are part of a complex home energy system that varies between homes. Instead, this review is based on publicly available information online from Panasonic and an interview with Sethi to get the most up-to-date information possible. 

Here's what you should know about the Panasonic Evervolt Home Battery. 

What do you get with the Panasonic Evervolt Home Battery?

The Evervolt Home Battery offers a modular design, making capacity selection and upgrades easier. Smaller battery modules also tend to make for an easier installation process. You'll also get a hybrid inverter with a solid 7.6 kilowatts of continuous backup power. But the real beauty of the hybrid inverter lies in the installation options it gives you. 

With a hybrid inverter, your battery can either be AC-coupled or DC-coupled, meaning it's compatible with a new solar panel system or a solar system that you already have installed on your home. Don't want solar panels? That's fine. The Evervolt Home Battery can also be installed as a standalone energy storage system without solar. 

Here are the Panasonic Evervolt Home Battery's specs at a glance.

System components

There are four main components that make up the Evervolt ecosystem:

• Battery cabinet.
• Battery modules.
  
• Hybrid inverter.
  
• Evervolt SmartBox.
  

It may sound like a lot, but you'll only have two boxes on the wall: the actual battery enclosure and the Evervolt SmartBox. The battery cabinet is a large enclosure that houses the battery modules, which are small lithium-ion batteries that can be added or removed from the battery cabinet to increase or decrease storage capacity. Instead of one giant battery, you have a few small batteries that connect together to incrementally increase storage capacity. 

The Evervolt comes with a hybrid inverter, meaning the system can be AC- or DC-coupled. A DC-coupled system will give you better performance and efficiency. This setup works best if you're installing solar and storage at the same time. You also won't have to buy a separate solar inverter, which typically costs around $2,000 or more.

Somebody who is getting solar and storage at the same time can completely avoid the PV inverter and save a lot of money. One inverter does everything, Sethi said

If you already have solar installed, you can still install the Evervolt. You'll just be going with an AC-coupled system instead of DC. Your battery's performance won't be as good as a DC-coupled setup, but the loss of efficiency is not a total dealbreaker. 

If you have multiple Evervolt batteries, you can even have an AC-coupled system and a DC-coupled system at the same time. 

There's also the Evervolt SmartBox. This is essentially an energy management device that provides a centralized place for all your wiring, connecting the battery, solar panel system and grid power all in one box. You'll be able to control up to six electrical loads. The SmartBox also contains the transfer switch, which flips your system to backup power when it detects a grid outage. 

Capacity and modularity

The Evervolt Home Battery is a modular system made up of a few small 4.5 kWh battery modules that are placed into the battery cabinet. Capacity can be increased by adding battery modules. Modular battery designs make it easy to size your system to something that's "just right" for your energy needs. 

The Evervolt's battery cabinet holds two, three or four battery modules. Each battery module has a usable capacity of 4.5 kWh. This gives you three sizes to choose from: 9 kWh, 13.5 kWh or 18 kWh. If 18 kWh isn't enough energy storage, you can install up to four additional units for a total of 72 kWh of storage space.

Performance and efficiency 

The performance specs you get with the Evervolt are pretty solid. What stands out most about the Evervolt's performance is its excellent power capabilities. The Evervolt can output 7.6 kW of continuous backup power at any capacity size when installed with solar. If installed without solar, you'll get less backup power with the 9 kWh Evervolt model (5.5 kW).

Battery capacity can be a little bit tricky. You typically aren't able to use all of a battery's capacity without shortening the lifespan of the battery. The amount of your battery's capacity that you can use safely is called its depth of discharge, and many we've seen have figures of at least 95%. The Evervolt's depth of discharge is a little bit lower, at 90%, meaning you won't be able to use as much of its total capacity. The figures we've used here are the battery's usable capacity, meaning we aren't factoring in that 10% of unusable capacity.

We also need to talk about round-trip efficiency, which is a measure of how much energy makes it into battery storage without getting lost. How efficient this battery is going to be is dependent on the coupling setup you have. DC-coupled systems are generally more efficient, and the Evervolt is no exception. When DC-coupled the Evervolt has a round-trip efficiency of 94% -- pretty good. As an AC-coupled system, the Evervolt's efficiency is much lower (89%), which is in line with the typical round-trip efficiency of home batteries (about 90%).

Warranty

Batteries are typically covered under a 10-year warranty, with a cycle life of 6,000 cycles and an end-of-warranty capacity guarantee of 70%. The Evervolt's warranty is a bit better than the average. It comes with a 12-year warranty, but its cycle life and capacity guarantee is the average described above, according to the spec sheet. That's not necessarily a bad thing though. Each Evervolt battery module has an approximate energy throughput of 13 MWh, which is higher than other individual battery modules we've seen. 

The Evervolt's 12-year warranty applies to the entire system too, so the SmartBox and inverter are covered too. Sethi said labor is included in the warranty as well, which is rare when it comes to battery warranties.

Years covered: The length of time your battery is covered under warranty. 

Cycle life and throughput: Most battery warranties cover a specific amount of battery cycles. This is also sometimes referred to as a battery's cycle life. A battery cycle is the act of draining and recharging your battery. In most cases, once your battery hits the cycle count listed in the warranty, your warranty expires. Alternatively, you'll also come across throughput. This is the expected amount of energy that a battery will deliver during its lifetime, set by the manufacturer. It's typically measured in megawatt hours.

End-of-warranty capacity guarantee: Battery capacity retention decreases the more you use it. A capacity guarantee is the manufacturer's guarantee that your battery will retain up to a certain percentage of its original capacity by the time your warranty ends. 

Customer support

If your battery system isn't behaving the way it should, your first point of contact should be your installer. They will most likely be the most helpful in diagnosing the problem since they are able to physically visit your property and are familiar with your system. But in the event you're unable to contact your installer, it's nice to know that you can reach out to the manufacturer with any questions or issues. 

We only found one avenue of contact with Panasonic specifically for support-related issues regarding their battery storage products. You just fill out an online contact form and wait for someone to contact you. Panasonic also has a general email you can reach out to if you have questions about their battery storage products, but it's more of a blanket email for general questions and documents.

How much does the Panasonic Evervolt Home Battery cost?

The Evervolt Home Battery is still relatively new to the market, so pricing details are still unclear. But Panasonic told us that the cost of the Evervolt Home Battery System is competitive with similar products. 

When it comes to battery pricing, you can generally expect to pay somewhere between $1,000 to $2,000 per kilowatt-hour of storage. You'll likely also pay between $2,000 to $3,000 for the installation of the battery. 

To get the most accurate price estimate for your home, you'll need to speak with a Panasonic-certified installer in your area. Or speak with a Panasonic representative. You might also want to explore multiple battery options from various installers in your local area.

Is the Panasonic Evervolt Home Battery my best choice?

Batteries aren't a one-size-fits-all type of product. The best battery for your home is one that meets your energy needs and budget. If power, modularity and a longer warranty matter to you, then the Evervolt Home Battery is a solid choice. The Evervolt also works with a variety of setups. It's compatible with new and existing solar systems, or you could install it without solar panels. 

But remember, you have more options than just the Evervolt. There are a ton of other battery offerings on the market that might be right for your home. And most installers are certified to install multiple battery brands. Explore battery offerings from several installers in your area before finalizing your decision. We also recommend gathering at least three quotes from installers in your area to get the best price possible.

How we evaluated the best solar batteries 

First let's be clear: Not every solar battery is right for every home. Solar is a very site-specific and personalized decision process, so it's a little tricky to pinpoint exactly which solar battery is the "best" battery for your home's energy needs without doing an on-site consultation. 

It should also be said that we didn't have any form of hands-on testing with any of the batteries we scored. This methodology also assumes you're purchasing a battery for the main purpose of using it for energy backup. If you mainly plan to use your battery for energy offset or to take part in a virtual power plant, there are likely better options than what we have featured in our reviews and rankings. We strongly encourage you to do your own research, as well as to speak with installers in your area. An installer will be able to get a better understanding of your home's energy use and what sort of system you might need. 

We used a few ways to evaluate and compare these batteries to find the stand-outs. Here's how we developed our list of top solar batteries.

First, we determined which categories would be used to evaluate each battery's performance, capacity and value. We also weighted each category. The weight of each category reflects the importance we felt was relevant to the average consumer: 

• Modularity: 20%
• Warranty: 20%
  
• Round-trip efficiency: 15%
  
• Power output: 15%
  
• Depth of discharge: 10%
  
• Price: 5%
  
• Price transparency: 5% 
  
• Customer support options: 10%
  

We looked at more than 15 of the most widely available batteries on the market and collected the data for each category to compare the numbers. Each category (for every battery) was given a rating (from 1 to 5) to evaluate which aspects of each battery were above average (among our list), just average or below average.

Panasonic Evervolt Home Battery FAQs