Tesla Powerwall 3 Review
The review was first published in Nov 2023. Latest update: Nov 2024.
In late 2023, numerous articles and photos of the Tesla Powerwall 3 emerged online. Soon after, Tesla officially announced the new Powerwall 3, and finally, in February 2024, the official datasheet was added to the documents section on Tesla’s website. Unlike the Powerwall 2, which is an AC-coupled battery system, the next-generation Powerwall 3 is an all-in-one solar and battery energy storage solution, similar to the Powerwall+ (Plus) released in the US in 2021, but more compact and far more powerful. However, while the new Powerwall 3 combines a solar inverter and battery storage into one simple unit, it still requires additional components to enable its full potential.
See our previous Tesla Powerwall 2 and Tesla Inverter reviews here.
New Specifications Revealed
At the All-Energy expo in Melbourne, Australia, I had the opportunity to examine the new Powerwall and speak to a Tesla applications engineer. With the official datasheet now available, we can confirm the US version of the Powerwall 3 features six individual solar connections (6 x MPPTs), enabling a maximum of 20kW of solar, or 3.3kW per MPPT. However, the Australian version is configured differently with 3 x high-powered 6.6kW solar MPPTs. Either way, this makes for an impressive piece of equipment and a substantial upgrade from the older Powerwalls. For extra battery capacity, the system is expandable with up to two additional 13.5kWh DC battery packs that can be DC-coupled for a combined total of 40.5kWh.
Powerwall 3 Key Features
Type: All-in-one solar & battery system (DC-coupled solar)
Capacity: 13.5 kWh (same as the Powerwall 2)
Scalability: Expandable up to 40.5 kWh using two additional 13.5kWh DC battery units.
Power rating: 11.5 kW continuous output (11.04 kW in Aus)
Peak power: 185 Amps LRA (less than 1 sec)
Solar input: Up to 20 kW of solar via 6 x MPPTs (or 3 high-current MPPTs)
Solar Voltage: MPPT voltage ranges from 150 to 480V
Weight: 130kg (287 Ibs)
Available: Yes - Online ordering is now available
Warranty: 10 years
Price: Starting from US$9,300* (AU$13,600), including backup gateway 2. *Pricing varies according to state. Excludes installation and any incentives or rebates. 13.5kWh battery expansion from US$5,500 per unit.
Download the official Tesla Powerwall 3 Datasheet (US Version).
Australian Release - Same but Different
In mid-August, six months after its release in the US, the new Powerwall 3 was officially launched in Australia. The down under version is virtually the same except for a few relatively minor changes, which appear to be made to conform to the unique Australian regulatory standards. The most significant is the slightly reduced power rating, down from 11.5 kW to 11.04 kW in backup mode. And the 10kW (43.5A @ 230VAC) grid connection rating. The other significant change is the number of solar MPPT connections, which has been changed from 6 x 13A low-current inputs to 3 x 26A high-current inputs. As explained below, the US version allows installers to modify (parallel) the MPPTs if required for higher-current solar panels. Strangely, this appears to be fixed in the Aus version. The Powerwall 3 is available as a single-phase unit only, but it can work on 3-phase or multi-phase sites, offering backup on one phase only. Like the Powerwall 2, there is no 3-phase version in the pipeline.
Unfortunately, in Australia, the cost of the Powerwall 3 is $1,500 higher than the Powerwall 2, coming in at $13,600, including the Gateway 2. However, considering the history of price fluctuations in Australia, this may drop at some point.
Download the official Tesla Powerwall 3 Datasheet - Australian Version.
The Powerwall 3 Vs Powerwall 2
The most crucial difference between the various Powerwall systems is that the new Powerwall 3 is an all-in-one (hybrid) system, including a solar inverter. Unlike the Powerwall 2, which is an AC battery that needs to be installed with a separate solar inverter. While not ideal, the new Powerwall can be used with most existing solar systems, including microinverters. For those familiar with the lesser-known Powerwall+ (plus), the Powerwall 3 is the essentially same type of all-in-one system but has been re-engineered with a much more powerful 11.5kW inverter and higher 20kW solar capacity.
One slight inconvenience the PW3 carries over from the Powerwall 2 is that it still requires the US$1,100 Gateway 2 unit to enable backup power of critical loads during a grid outage. However, like the other Powerwalls, the PW3 has an alternative compact and rather ingenious Backup Switch to enable whole home backup. The more affordable Backup Switch, available in the US only, can be installed behind the utility meter or hidden inside a meter panel for a more streamlined solution. Since the PW3 has a much higher 11.5kW power rating, it is better suited for whole-home backup, although the amount of time the system can operate in off-grid mode is still limited by the battery capacity, so during poor weather, users will have to monitor the usage closely (unless they install multiple battery units).
Battery Efficiency
The existing Powerwall 2 is an AC-coupled battery system, meaning it does not contain a solar inverter but can be charged from any AC course, including an existing solar system or microinverters. On the other hand, both the Powerwall Plus and Powerwall 3 are DC-coupled hybrid systems that contain an inbuilt solar inverter and directly charge the battery from connected solar panels. Hybrid systems are more efficient since the battery is DC and the solar array is DC, so no DC to AC power conversion is required when charging from solar.
When we examine the power conversion in more detail, solar DC charging losses are typically less than 3%. In comparison, the AC-coupled Powerwall 2 requires power conversion from DC to AC at the solar inverter and then from AC to DC during charging, which results in a combined loss of around 7%. Lastly, the power conversion from DC to AC when discharging results in around 3% loss. The total charge and discharge losses are used to calculate what is known as the round-trip efficiency.
Powerwall 2 - AC-coupled battery = 92 - 93% charging efficiency
Powerwall 3 - DC-coupled battery = 96 - 97% charging efficiency
Comparsion chart of the Powerwall 2, Powerwall+, and Powerwall 3 features and specifications
Performance and Power
One of the most significant performance gains of the new Powerwall is the impressive 11.5kW continuous power rating (on-grid), which is around 60% higher than the 7kW Powerwall+ and 120% higher than the Powerwall 2. This much power would be overkill for smaller, efficient households. However, many modern all-electric homes with solar EV charging require a high-power system, and this is where the extra grunt of the Powerwall 3 is ideal. It's worth noting an EV charger alone can draw from 7kW up to 9kW at full power. For larger power requirements, up to 4 Powerwall 3s can be installed in parallel to provide up to 40 kW of inverter capacity with up to 80 kW of solar. However, most sites requiring this amount of energy would also have a 3-phase power connection, while the Powerwall 3 is only available in single-phase or split-phase (120/240V in the US).
Backup Power Rating
The backup power rating is 11.5kW continuous (11.04kW in the Australian version), more than enough to support the power needs of most homes during a blackout, meaning whole-home backup should not be a problem. Many alternative systems have limited backup power of 5 to 6kW, generally resulting in only essential household load circuits being supplied during a power outage. This may not be required with the Powerwall 3, but users must still actively manage the loads to ensure the battery is not depleted too fast if solar is unavailable.
Limited AC charging
One notable limitation is the 5kW battery charge power, meaning charging a flat battery will take almost 2.5 hours. So, even with the solar maxed out at 20kW, the battery can only be charged at 5kW, resulting in excess energy being exported or ‘clipped’ during sunny weather when the loads are low. Of course, this will not be an issue if you have significant daytime loads or EV charging. This also highlights a difference in the LFP battery chemistry used in the PW3. Lithium Ferro Phosphate (LFP) cells generally do not tolerate rapid charging, unlike other lithium chemistries like NMC used in the Powerwall 2. However, regarding battery lifespan, I would consider this a positive, as it is well known that battery degradation is reduced at lower charging rates, meaning longer life. As explained later, LFP cells also last longer, are more thermally stable, and are unlikely to go into thermal runaway (catch fire) even if damaged.
Extract from the Powerwall 3 datasheet highlighting the battery charge power and peak Amp rating.
Powerwall 3 is not (yet) certified for off-grid use
In regards to off-grid functionality, Tesla has not stated that off-grid use is not supported at this time. Like most hybrid all-in-one systems, the Powerwall inverter is grid-forming and can operate in off-grid (backup) mode without problem, but it lacks some key features needed for year-round off-grid operation. The off-grid limitations are primarily due to the inability of the Powerwall 3 and Gateway to connect, integrate, and manage external backup power sources such as a backup generator. Fortunately, there are many high-performance off-grid solar systems available.
Peak Power Output
Powerwall 3 Power Ratings (*est)
11.5 kW Continuous Power
15.0 kW Peak Power (10 seconds) *
185 Amp Surge (less than 1 second)
While the peak power rating is not officially listed, we can make some assumptions based on what we know about the Powerwall 3’s little brother, the Powerwall+, which offers 10kW of peak power for 10 seconds. Additionally, we know the LRA (locked rotor amps) rating of the Powerwall 3 is an impressive 185A (initially listed at 150A), which is the maximum amps the inverter can supply (for less than 1 second) when starting a motor such as a compressor or large pump from a standstill. For clarification, the LRA rating, also known as the inrush current, can be described as the absolute peak amps or the maximum surge rating that can be sustained for less than 1 second.
Tesla Powerwall 3 battery continuous and peak power comparison chart.
The older Powerwall+ had an LRA rating of 118A, equivalent to 28kVA at 240V. In comparison, the new PW3 has a significantly higher LRA of 185A, equal to an impressive 44kVA at 240V. For those unfamiliar with kVA (kilo-Volt-Amps), the kW rating roughly equates to 0.8 x kVA. Therefore, 44kVA is approximately 35kW (or 17.5kVA at 120V). This substantial power output is more than enough to start almost any single-phase motor or clunky old HVAC compressor. However, unlike the peak power rating, which can generally be sustained for up to 10 seconds, the absolute maximum surge or LRA output is less than 1 second. It is worth noting the LRA is usually measured under standard test conditions at 25°C, so this will likely be lower at higher ambient temperatures or during sustained high continuous loads.
Pro tip: Using a load calculator is the best way to estimate the maximum peak and surge loads.
Powerwall 3 In-depth Analysis
Although the exposed cast aluminium housing of the Powerwall 3 looks and feels very solid, it is less attractive than the previous Powerwall 2. However, the new exposed outer shell is more about function than aesthetics, as the housing also acts as a massive heat sink to disperse heat and regulate the internal temperature. Additionally, it’s no surprise that the weight is around 15kg greater than that of the Powerwall 2, considering that a typical 10kW solar inverter weighs around this amount.
The size has changed; the new Powerwall 3 is 50mm shorter, 150mm narrower and 30mm deeper than the Powerwall 2. Considering the new PW3 also contains a solar inverter and is comparable to the much larger Powerwall Plus, the compact size is rather impressive. Aesthetics aside, one of the most exciting aspects is the high power rating, a remarkable 11.5kW continuous, making it one of the most powerful, all-in-one, single-phase battery systems available.
Powerwall 3 main specifications and features updated Feb 2024 - Image credit Tesla
Redesigned cooling system
Powerwall 3 active cooling system
Unlike the previous Powerwall 2, which relied on a complex liquid thermal management system, the new Powerwall uses a relatively simple active or fan-forced cooling system. The new design features a lower cold air intake, which takes advantage of natural convection to help cool the inverter. This works quite simply: as the large aluminium housing (heat sink) warms up, hot air rises, causing a natural flow of air, and the built-in fan increases this flow, depending on the temperature. Not surprisingly, this is how many solar inverters and all-in-one hybrid systems are cooled. However, Tesla has taken this one step further and integrated dual fans and a unique air duct system, which draws air along the front and rear of the battery unit.
New LFP cells
Besides being much simpler and less expensive, a logical reason why the cooling system has been re-engineered is due to the new LFP or Lithium Ferro Phosphate cells used in the Powerwall 3. Like many other battery manufacturers, Tesla has transitioned from Lithium NMC cells to LFP cells. The NMC or Nickel-Manganese-Cobalt cells previously used were similar to the batteries used in Tesla’s electric vehicles and require precise thermal regulation due to the limited operating temperature and increased risk of a thermal runaway at elevated temperatures. However, over recent years, LFP cell technology has advanced significantly and is much safer, longer lasting, and, most importantly, more thermally stable than NMC cells. This, in turn, means the cooling system can be simplified without any adverse effects. Importantly, LFP cells also contain no Cobalt. Issues around cobalt mining have been contentious, which is why most battery manufacturers, including Tesla, are working towards phasing out cobalt use over the next few years.
Powerwall 3 with the front cover removed showing the main internal features
More MPPTs but limited voltage range
While the specifications are impressive overall, one constraint is the slightly limited upper solar MPPT operating voltage. Solar panels are connected in strings, varying in length from as little as three panels up to 14 panels or higher. The longer the string, the higher the operating voltage. Most modern solar inverters operate in the 100 to 550V range, with a maximum of 600V. The Powerwall 3 specifications show a 150V to 480V operating (MPPT) voltage range and a maximum of 600V. This would result in slightly fewer panels per string. The 480V upper MPPT limit is the same as the Tesla solar inverter, suggesting it uses the same MPPTs. However, considering the PW3 contains an impressive six independent MPPTs, the limited upper voltage is not a major concern as the combined 20kW solar capacity is far greater than most other systems.
Systems designers can use the Photonik Solar String Voltage Calculator to determine the minimum and maximum string voltage.
Low MPPT input current rating
As with the Tesla solar inverter, another limitation is the 13A input current rating (per MPPT). Several 440W+ solar panels currently have a current (Imp) rating above 13A, which could result in some clipping of the solar output under ideal conditions. However, most residential solar panels operate in the 12A to 13A range, so it will not be an issue in most situations. Although, due to the ever-increasing panel power output, there are already some new panels rated up to 500W with current ratings above 14A, making this a possible issue in the near future. While the MPPT maximum operating input current is 13A, the short-circuit current rating (Isc) is not much higher at only 15A. I expected the Isc to be 17A, as per the Tesla solar inverter.
Solution for high-current panels
Fortunately, there is one workaround which is noted in the fine print on the Powerwall 3 datasheet, which states, “Where the DC input current exceeds the MPPT rating, a jumper can be used to combine two MPPTs into a single input to intake DC current up to 26 A (Imp) can be implemented if high-current panels are used”. This essentially means the six solar MPPTs can be combined in pairs to create three high-current MPPTs rated at 26A and with a max Isc (short-circuit) current rating of 30A (Isc), which is more than enough even for large commercial 600W+ panels.
How much does the Powerwall 3 cost?
Powerwall 3 US pricing example
Tesla officially listed the Powerwall 3 for order online via their website in February 2024. Due to the much higher power output and additional features, we assumed it would be significantly more expensive than the Powerwall 2. However, the US price was initially listed as being the same as the current Powerwall’s price of US$8,400, including the backup gateway, which costs $1,100 if purchased separately. However, the actual cost appears to vary widely depending on which state you are in, local regulations, and certified installer rates. For example, in Houston, Texas, the price is shown as US $10,209. However, after local incentives are factored in, the price is almost halved at $5,286, making it a very affordable option. Note the price does not include installation, wiring, switchboard modifications or solar.
The price of the additional battery expansion units can also vary widely from US$5,500 to $7,300 per unit, depending on which state you are in. Again, pricing appears to be dependent on the local Tesla-certified installers in the state or region.
In Australia, the cost is $13,600, including the Gateway 2, which is $1,500 more than the Powerwall 2. Note the price does not include freight, installation, possible switchboard modifications or upgrades, or solar array components, including panels, racking, wiring, isolators, rapid shutdown, and other equipment.
Should you order the Powerwall 3?
The short answer is yes if you do not have an existing solar system or if you have a larger home requiring a lot of backup power. However, for those with a substantial size solar system already installed, there are many alternative and affordable options for adding battery storage to your home. Additionally, the relatively large 13.5kWh battery may be oversized for smaller, energy-efficient households, and most alternative systems offer more modular, scalable battery options. Try our solar and battery sizing calculator to help determine whether the Powerwall 3 system is suitable for your home.
The Powerwall 3 is a well-engineered, feature-packed system from Tesla. The impressive 11.5kW power rating and up to 20kW of solar input make this a great solution for modern all-electric homes with solar EV charging. For those wanting to add battery storage to an existing solar system, the Powerwall 2 might be a better option. Alternatively, replacing your existing solar inverter with a Hybrid inverter, such as those from the Deye, Sungrow or Fronius, could be a much better option and enables more flexible battery storage options. If you have a small or undersized solar system and are considering upgrading it in the future, Powerwall 3 has the advantage of 6 independent MPPTs and up to 20kW of solar.
If you live outside the US, UK, Germany or Australia and require a large, powerful solar battery backup system, there are many other high-quality battery systems worth considering. Our detailed solar battery system comparison charts show some of the numerous available options.
