Tesla Powerwall 3 Review: The Most Popular Home Battery, Now More Powerful

7.4

Tesla Powerwall 3

Like

• Unlimited cycle warranty
• High power output
• Well-rounded performance and efficiency

Don't like

• Lacking modularity
• Not compatible with other Powerwall models

If you're looking for a home energy backup or a solar battery, you'll most likely encounter the Tesla Powerwall. It is, far and away, the most popular home battery in the US.

Not just a maker of electric vehicles, Tesla has made a name for itself in the solar industry since acquiring SolarCity in 2016. Tesla introduced the first Powerwall model in 2015 but didn't start mass production of the battery until 2017. The current Tesla Powerwall models on the market are the Powerwall 2, Powerwall Plus and Powerwall 3. 

Both the Powerwall 2 and Powerwall Plus batteries are interesting because they're just so average, and strangely enough, we mean that in a good way. These batteries are on par with their competition in almost every way. There are a few stand-outs: an unlimited-cycle warranty, large capacity, stackability, well-rounded specs and some interesting app features. The Powerwall's specifications don't stand out from the battery crowd too much; nor does it have any glaring weaknesses. But it has one of the lowest prices we've seen, making it one of the most affordable batteries on the market today. 

The Powerwall 3, Tesla's latest home battery model, improves on the existing specifications of the previous models while still keeping the same unlimited-cycle warranty as its ancestors.

What do I get with a Tesla Powerwall?

While the Tesla Powerwall 3 outshines the previous models in nearly every way, the Powerwall 2 isn't a bad pick either. In our scoring, it received at least an average rating in just about every category. It's also a good value battery because it tends to be cheaper than its competitors. 

The Powerwall 2 and Powerwall Plus batteries are similar to one another -- the difference is how they interact with your home's energy system. The Powerwall is compatible with new and existing solar panel systems. It can also work as a standalone home battery without solar panels. On the other hand, the Powerwall Plus battery is integrated with a Tesla Solar Inverter. Both Tesla batteries can be installed with other brands of solar panels. You don't need Tesla solar panels to install a Powerwall.

The Tesla Powerwall 3 can't be installed alongside other Powerwall models.

If you already have a Powerwall 2 or Powerwall Plus installed, you won't be able to add the Powerwall 3 to that system.

Tesla Powerwall 3

Like:

• Unlimited cycle warranty

• High power output 

• Well-rounded performance and efficiency

Don't like:

• Lacking modularity 

• No pricing information

• Not compatible with other Powerwall models

See at Tesla

Tesla Powerwall 2

Like:

• Well-rounded specs 
  
• Unlimited cycle warranty

Don't like:

• Lacking modularity
• Lower power output

See at Tesla

Tesla Powerwall Plus

Like:

• Well-rounded specs
• Higher backup (off-grid) power output 
• Unlimited cycle warranty
• Integrated solar inverter

Don't like:

• Lacking modularity
• Lower on-grid power output (same as Powerwall 2)

See at Tesla

Capacity and modularity

All three Tesla batteries have a 13.5 kilowatt-hour energy capacity, a good size for a home battery backup. Depending on how much of your home you want to supply power to during an outage, you'll likely need multiple Powerwalls. One Tesla Powerwall battery is ideal for partial home backup, while whole-home backup will most likely require multiple Powerwalls. You can install up to 10 Powerwall 2 units or Powerwall Plus units for a total of 135 kWh of energy storage. Both battery models can be mixed. 

The Powerwall 3 is not compatible with the Powerwall 2 and Powerwall Plus models. If you decide to go with the Powerwall 3, you can install up to four units for a total capacity of 54 kWh.

Tesla Powerwall batteries do not feature a modular design, making capacity upgrades difficult and expensive. If you find yourself needing a capacity upgrade, you'll have to buy another 13.5-kWh battery.

Performance and efficiency

The Powerwall 2 is about average efficiency for the batteries we examined. The Powerwall 2's round-trip efficiency is 90%, meaning 10% of the electricity gets lost on its way to the battery for storage. A round-trip efficiency of 90% (or higher) is typical for lithium-ion batteries. The Powerwall Plus also has a round-trip efficiency of 90%. The Tesla Powerwall 3's round-trip efficiency is about the same as the others as well, at 89%.

All three Tesla Powerwall batteries have a 100% depth of discharge -- the best it can be. Depth of discharge is the amount of energy you can drain from the battery at once without damaging it. In essence, it's how much of your battery's capacity you can actually use relative to its maximum capacity. However, just because you can drain the majority of your battery all at once doesn't mean you should. One of the main factors affecting a battery's lifespan is the number of times it gets cycled. A battery cycle is the process of discharging (draining) your battery and then recharging it. In other words, the fewer times you fully cycle your battery, the better. 

Now we get to the power output. The Powerwall 2 is the industry average in terms of power. It has a peak power output of 7 kW and a continuous power output of 5 kW. A battery's peak power output is the amount of power the battery can push out all at once without damaging anything. This type of power is typically used when activating larger loads or appliances, such as when your AC or heat kicks on. Continuous power output is the amount of power the battery can handle at any time. 

The Tesla Powerwall 3 provides a huge upgrade in power, with a continuous power output of 11.5 kW. This is more than twice as powerful as the older Powerwall models. The Tesla Powerwall 2 and Powerwall Plus have the same on-grid power output capabilities, but the Powerwall Plus has far better backup power output capabilities, with a peak power output rating of 22 kW in full sun or 10 kW with no sun and a continuous power output rating of 9.6 kW in full sun or 7 kW with no sun.

Read more: Just looking for an emergency backup? Check out portable solar panels and solar generators.

Warranty 

All three Powerwall batteries fall under the same warranty, and it's one of the best warranties we've seen for home batteries.

Years covered: This is the length of time your battery is covered under warranty. A 10-year warranty is the industry standard for solar batteries.

Cycles covered: The number of times you cycle your battery (drain and recharge it) affects its lifespan, which is why many manufacturers will include a cycle or throughput clause in their warranty. Once you hit the designated cycle count set by the manufacturer, your warranty will expire, even if you still might have a few years of coverage left. The Tesla Powerwall is warranted for unlimited cycles, which is rare in the battery world. The typical battery warranty covers 4,000 to 6,000 cycles, making Tesla's unlimited-cycle warranty more competitive. 

End-of-warranty capacity guarantee: Batteries start to lose the ability to hold a charge over time, so most manufacturers will include an end-of-warranty capacity guarantee. This is the manufacturer's guarantee that your battery will be able to store a specific percentage amount of energy by the time your warranty period is up. Tesla guarantees the Powerwall will retain at least 70% of its original capacity by the time your warranty ends.

Customer support

If you're ever having trouble with your battery system, most manufacturers are likely going to push you to contact your installer. Since your installer can physically come to your property and diagnose the problem, they're probably going to be more helpful in solving your problem versus calling the manufacturer. However, customer support options from the manufacturer are still helpful for those who aren't able to get in touch with their installer, or maybe just have a quick troubleshooting question or issue.

Tesla has a fair amount of ways you can reach out for support if you're having trouble with your Powerwall. If you need a more immediate response, you can call their support number. There is a live chat, but it's primarily for sales, not customer support. There's also a support email address. If you think the issue might be a relatively simple solution, Tesla has some troubleshooting FAQs and quick articles that could help you out.

Tesla app

Using the Tesla app, you'll be able to view and monitor your home's energy usage, as well as analyze and compare data about your home's past and current energy production. Powerwall can also be customized to help support your energy goals by using the different control mode settings through the app. These settings essentially change how your battery charges and discharges. Keep in mind that some features and settings are only available when paired with solar panels. 

You can also set a designated percentage of your Powerwall's capacity aside to be reserved for backup power in the event of grid outages. Tesla recommends setting a backup reserve of 20% when using the backup reserve setting, but you can set it to whatever you like. 

The Tesla app is not without its flaws. Online reviews show complaints about frequent glitches and the unreliability of the app, with some people saying it only seems to work half the time they use it.

Tesla Powerwall 2 vs. Tesla Powerwall Plus

There isn't much of a difference between the Powerwall 2 and Powerwall Plus. The Tesla Powerwall 2 is just a battery and can be installed with or without solar panels. The Tesla Powerwall Plus is a regular Tesla Powerwall 2 battery that has been integrated with a Tesla Solar Inverter. The Powerwall Plus is designed specifically for solar installations, while the regular Powerwall 2 model is compatible with or without solar panels. 

Both batteries have the same capacity (13.5 kWh). The Powerwall Plus has a much higher backup power output rating, making it a better option if you are installing a new system and have plans to go completely or partially off the power grid. Most homes will likely need more than one Tesla battery (of any model) to live completely off-grid. Both Tesla batteries are interchangeable, meaning you can install a mix of up to 10 Powerwall 2 and Powerwall Plus batteries. 

How much does the Tesla Powerwall cost?

Home battery systems are anything but cheap. However, the Powerwall batteries do tend to be a bit cheaper than some other alternatives. Each Tesla Powerwall model will likely cost you between $8,400 and $13,000. Pricing depends on your location and other installation and labor costs. When it comes to batteries, you can generally expect to pay between $1,000 and $2,000 per kilowatt-hour of energy storage. 

To get the most accurate pricing information, talk to a Tesla-certified installer in your area, and get multiple quotes to get the best price possible. Gathering a mix of quotes from national and local installers will give you the most price variety.

Is the Tesla Powerwall my best choice?

All the Powerwall batteries are well-rounded in capacity, performance and efficiency. And the Tesla Powerwall 3 improves on the power output of the previous models, with over twice as much continuous power (11.5 kW). These batteries also come with one of the best warranties in the industry. 

But is the Tesla Powerwall your best choice? That depends. The best battery for your home is one that fits your household's energy needs and what you are looking to accomplish with a battery installation. Most installers offer more than one brand of battery, so explore other battery options from installers in your area if you can. Try to get multiple quotes 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. Choosing solar is a 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 assumes you're buying 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 those listed 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 person: 

• 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.

Frequently asked questions