As home battery storage continues to grow in popularity, the Tesla Powerwall 3 is no longer standing alone at the top. More premium solutions are entering the UK market, and one of the most notable newcomers is the Fox ESS EVO Battery, launched in 2025. At first glance, it could easily be mistaken for the Tesla Powerwall’s identical twin. Both offer sleek design, high performance, and the ability to help households make the most of their solar energy while saving money on your energy bills.
But how do they really compare? From design and installation to warranties, capacity, and everyday performance, each battery brings its own strengths and differences that could influence which is the best solar battery for your home. In this blog, we’ll take a closer look at the Tesla Powerwall 3 vs Fox ESS EVO battery side by side, giving you a clear comparison to help you decide which system is the right fit for your energy needs.
| Tesla Powerwall 3 | Fox ESS EVO Battery | |
|---|---|---|
| Usable Capacity | 13.5kWh | 9.73kWh |
| Maximum Storage Capacity | 94.5kWh - 4 Main Powerwall Units, 3 Extension Packs Per Powerwall 3 | 29.2kWh - 3 Batteries in Parallel Battery only expansion packs available in 2026. |
| Max Charge Rate | 5 kW with 1 Battery 8kW with the Addition of at least 1 Expansion Pack | 10kW ( Depending on the inverter) |
| Max Discharge Rate | 11.04 kW | 10kW |
| IP Rating | Powerwall - IP67 Gateway - IP55 | EVO - IP66 EPS BOX - IP65 |
| Inverter Size | Up to 11kW | 3.7kW (Soon) 5, 8 and 10kW |
| Maximum Solar Input | Up to 20kW | Up to 20kW |
| Round Trip Efficiency | 89% | 94% |
| Cell Technology | Lithium Ferro Phosphate (LFP) | Lithium Ferro Phosphate (LFP) |
| Size | Powerwall - 1105 x 609 x 193 mm Expansion Pack - 1105 x 609 x 168 mm Gateway - 584 x 380 x 127 mm | EVO - 584 x 1009 x 197 mm EPS BOX - 420 × 550 × 138.5 mm |
| Weight | Powerwall Wall - 132 kg Expansion Pack - 110 kg Gateway - 11.4 kg | EVO - 113 kg EPS BOX - 16kg |
| Monitoring | Tesla Monitoring 3.6 from 1.8K Ratings (App Store) | FoxCloud 2.0 2.1 from 199 Ratings (App Store) |
| Warranty | 10 Years (unlimited cycles, 80% capacity retention) | 12 years, or 6,000 Cycles. |
Fox ESS Vs Tesla
Tesla
- Founded: 2003
- Country of Origin: USA
- Product Maturity: October 2016
- Warranty: 10-year warranty with unlimited cycles and 80% capacity retention
Fox Ess
- Founded: 2019
- Country of Origin: China
- Product Maturity: September 2025
- Warranty: 12 Years. With a 6,000 Cycle Life
Tesla VS Fox ESS: Brand & Product Maturity
The Reigning Champion – Tesla Powerwall 3
Tesla, founded in 2003, has grown from an ambitious electric vehicle start-up into one of the world’s most recognisable brands in clean energy and sustainable technology. The company installed its very first Powerwall battery in May 2015, marking the beginning of its journey into residential energy storage. By 2017, mass production of the Powerwall 2, a battery combined with an AC controller, was underway at Tesla’s Gigafactory in Nevada.
Fast forward to 2023, Tesla launched the Powerwall 3, the third generation in its residential battery series. Unlike its predecessors, it combines a battery and hybrid inverter into a single all-in-one solution, setting a new benchmark for simplicity, efficiency, and design. With ongoing innovation in solar and battery technology, Tesla continues to establish itself as a pioneer in the residential energy storage market.
Tesla’s global influence has been widely recognised. In 2024, it received a Global Recognition Award for its advancements in sustainable energy and transportation technologies, underlining its leadership in the transition to renewable energy.
As of 2025, Tesla has installed over 1 million Powerwalls worldwide, making it one of the most widely adopted residential energy storage solutions.
The Contender – Fox ESS EVO Battery Series
Designed to be seen and built to perform, the EVO is Fox ESS’ most advanced battery solution yet. It combines a high-performance inverter with a large-capacity 10.24kWh LFP battery in a single elegant unit. Offering a clean installation, everything is built into one weatherproof enclosure, for a a cleaner, faster installation, with no external cabling required. A 5kWh battery version and expansion packs are also in development, and it’s no surprise that Fox ESS earned the EUPD Top Innovation Award in Storage (2025) for this breakthrough.
Although the EVO is a newcomer, Fox ESS is far from new to the market. Already offering a wide range of inverters and solar batteries in the UK, the company is recognised as a BNEF Tier 1 energy storage manufacturer, praised for its product quality, innovation, market influence, and financial strength. Despite only entering the UK market in 2019, Fox ESS has quickly become a leader, holding a 35% share of the domestic solar and storage sector. Globally, they have shipped 870,000+ batteries, 1.58 million+ inverters, and connected over 200,000 systems, ranking 2nd worldwide for residential energy storage shipments.
Fox ESS is a Sino-British partnership, backed by significant stakeholders including the Tsingshan Group, a Global Fortune 500 company and the world’s leading producer of nickel, as well as one of the top four holders of lithium resources globally. Making Fox ESS a serious contender.
Warranty
When it comes to warranties, the Tesla Powerwall 3 includes a 10-year warranty covering the battery, Tesla Gateway, and any expansion packs, guaranteeing 80% capacity retention at the end of the period. Importantly, the warranty allows for unlimited charge cycles, provided the system remains connected to the internet. This highly competitive coverage reflects Tesla’s strength as a global brand with years of proven experience.
By comparison, the Fox ESS EVO Battery offers a 12-year warranty , provided it is registered online within 36 months and linked to the Fox Cloud platform via a Fox datalogger for remote monitoring. It also comes with a rated lifespan of 6,000 cycles, guaranteeing a 70% retain capacity, which is inline with many other leading battery brands.
Product Form
If you removed all branding and placed the Tesla Powerwall 3 and Fox ESS EVO Battery side by side, at first glance they could almost pass as the same product. Both feature a sleek, white glossy finish and are designed as all-in-one battery systems, crafted with premium, aesthetic-conscious installations in mind. In terms of form, they are nearly identical. The Tesla Powerwall 3 weighs in at 132kg, while the Fox ESS EVO is slightly lighter at 113kg, a detail installers will appreciate, as it makes handling and installation a little easier.
Both batteries can be wall-mounted or floor-mounted and are suitable for safe indoor and outdoor installation in the UK. The Tesla Powerwall operates in temperatures from -20°C to +40°C, while the Fox ESS EVO has a slightly broader range of -20°C to +55°C, giving it an edge in warmer climates. Direct sun exposure in summer isn’t recommended for either, but both perform well in UK winters thanks to internal battery warm-up elements.
The Tesla battery uses an industry-leading Active Thermal Management system, which monitors external temperatures and even weather forecasts, heating individual cells until they reach their optimal operating range. While Tesla’s system is more advanced in terms of temperature management for outdoor installation, the Fox EVO includes a built-in aerosol fire suppression unit. This safety feature is triggered at 170°C or when a flame is detected, offering extra peace of mind for indoor installations.
Although the Tesla Powerwall offers a slightly stronger IP rating, both the Fox ESS EVO battery and its backup box are rated for outdoor installation. The Tesla Solar Gateway, however, remains at IP55, meaning additional protection may be required outdoors.
Battery Capacity & Scalability
Tesla Powerwall 3
- 13.5kWh usable capacity.
- Supports 4 stacks per phase, with 3 additional Tesla expansion packs.
- Expandable up to 94.5kWh of battery capacity per phase.
- The round trip efficiency of the system is 89% meaning that for every 100kWh stored in the system you will get 89kWh back out.
Fox ESS EVO Battery
- 9.73kWh usable capacity.
- Supports 3 EVO batteries in parallel Per Stack, for a Maximum of 29.2kWh of useable capacity.
- The round trip efficiency of the system is 93.8%, meaning that for every 100kWh stored in the system you will get 93.8kWh back out.
In terms of usable capacity, Tesla takes the lead. The Powerwall 3 offers a 100% depth of discharge, allowing homeowners to access the full 13.5kWh of energy storage. By comparison, the Fox ESS EVO Battery is advertised as a 10.24kWh unit, but with a 95% depth of discharge, only 9.73kWh is actually usable.
If we compare the Fox ESS EVO Battery vs the Tesla Powerwall 3 in terms of scalability, the EVO battery is currently more limited. The Powerwall 3 supports up to four stacks per phase, with three additional expansion packs, providing a total usable capacity of 94.5kWh per phase.
When the Powerwall 3 was first released, system expansion was only possible by paralleling units, until the Powerwall Expansion Pack became available. Fox ESS appears to be following a similar approach, with battery-only expansion packs scheduled for release in 2026. For now, expanding an EVO system requires adding an additional inverter, which can be costly if the extra inverter isn’t otherwise needed.
The Fox ESS EVO Battery boasts an impressive high round-trip efficiency, with a PV-to-Battery efficiency of 97.3% and a Battery-to-AC efficiency of 96.4%, giving an overall Solar-to-Battery-to-Home/Grid efficiency of 93.8%.
In comparison, the Tesla Powerwall 3 has a round-trip efficiency of 89%, meaning more energy is lost during the conversion process. When looking at Solar-to-Home/Grid efficiency, the Tesla battery is rated 97.5%, while the Fox ESS EVO achieves 97.6%, or 97.2% in Europe.
Inverter Size & Scalability
Tesla Powerwall 3
- Comes with a 11.04kW Built-in hybrid Inverter
- The integrated inverter can be adjusted in size through the software, 3.68 kW – 11.5 kW.
- Supports up to 20kW of maximum PV Power per phase.
- Voltage Range – 60 to 550V
- Supports 3 MPPT
Fox ESS EVO Battery
- Offers 3 built-in hybrid inverter options, a 5, 8 and 10kW model dependent on your needs. A G98 3.7kW version will also be available shortly.
- Supports up to 20kW of maximum PV Power per phase.
- Voltage Range – 75V to 600V
- 2 to 3 MPPTs depending on inverter choice.
The Tesla Powerwall 3 comes with a built-in 11.04kW hybrid inverter, which can be configured at commissioning to any rating between 3.68kW and 11.04kW. This flexibility is especially useful if your DNO provider initially imposes restrictions that are later amended, allowing you to easily adjust without changing hardware.
By comparison, the Fox ESS EVO series currently offers three inverter sizes, 5kW, 8kW, and 10kW, with a 3.7kW model due soon. This lets you select the inverter that best fits your system requirements from the outset. While this may limit flexibility for adding more solar panels in the future, it ensures you only pay for the hardware you’ll actually use, making it a more cost-effective solution in the short term.
When it comes to PV input, both the Fox ESS EVO Battery and the Tesla Powerwall 3 are evenly matched. Each supports up to 20kW of solar with three MPPT inputs, making them excellent choices for homes with abundant roof space and high energy demands. Even their input voltage ranges are very similar.
The standout difference lies in their charge and discharge rates. For the Tesla Powerwall 3, the discharge rate is dictated by the size of the inverter. Set at 11.04kW, the Powerwall can discharge its full capacity in about 1 hour 13 minutes. With a much slower charge rate of 5kW, it takes a single Powerwall 2 hours 42 minutes to charge to full capacity. However, adding a second unit increases the charge rate to 8kW.
By contrast, the Fox ESS EVO Battery can charge and discharge at the inverter’s full rate. With the 10kW model, the battery can both fully charge and discharge in just 58 minutes. This speed is especially valuable for homeowners using Smart Tariffs, as it allows up to four EVO batteries to fully charge within a typical 4-hour off-peak window.
Price: Is Tesla Powerwall 3 or Fox ESS EVO Battery Cheaper?
| Battery | Total Usable Capacity | Estimated Installation Cost | Average Cost per kWh |
|---|---|---|---|
| Tesla Powerwall 3 (No Gateway) | 13.5kWh | £7000 - £7500 | £537 |
| Fox ESS EVO Battery (No Gateway) | 9.73kWh | £5500 - £6000 | £590 |
*This price includes installation, IWA registration, MCS certification, DNO registration and 5 years workmanship warranty.
Based on the figures, the Tesla Powerwall 3 offers a more cost-effective price per usable kilowatt-hour (kWh), being approximately £53.92 cheaper per kWh than the Fox ESS EVO Battery. While the Fox ESS EVO may have a lower upfront cost for those on a tighter budget, the Tesla Powerwall 3 is offers better value for those with larger storage requirements.
Tesla or Fox ESS: Home EcoSystem
Both Tesla and Fox ESS offer an ecosystem of interconnected products and services designed to deliver a seamless energy experience.
The Tesla ecosystem integrates home battery storage, solar, electric vehicles, and the supercharging network. This allows homeowners to generate, store, use, and charge entirely within Tesla’s world. With its strong focus on EVs, the Powerwall 3 is an ideal choice for homeowners looking to invest more deeply into the Tesla Motors brand.
The Fox ESS ecosystem is a comprehensive suite of solutions that combine solar, battery storage, and energy management for both homes and businesses. It includes solar inverters, battery systems, EV chargers, and links with other smart technologies such as the Hive ecosystem. The Fox ESS ecosystem also incorporates its very own Air Source Heat Pump, creating a wider smart energy network for sustainable living. This interconnected approach enables homeowners to efficiently capture, store, and use their solar energy, all managed through intelligent monitoring platforms.
Tesla Electric
Choosing a Tesla Powerwall battery opens access to Tesla Electric, an energy plan designed exclusively for Powerwall and Tesla EV owners. Already launched in the US, Tesla has applied to Ofgem to bring the service to the UK, offering a 100% renewable electricity tariff for homes and businesses in England, Scotland, and Wales. The service will be managed via the Tesla mobile app and will leverage Tesla’s existing network of local battery storage and solar installations to reduce reliance on the centralised grid. Powerwall users will be able to store energy when it’s cheap and discharge excess energy during peak times for a profit, helping to stabilise the grid in the meantime. The plan may also offer unlimited charging for Tesla EV owners. By optimising energy usage and potentially offering low-cost renewable energy, the service aims to provide more affordable energy. Tesla Electric is designed to integrate seamlessly with existing Tesla products and is comparable to tariffs such as Intelligent Octopus Go and Intelligent Octopus Flux.
Tesla VPP
Another benefit of choosing a Tesla Powerwall installation in the UK is access to the Tesla Virtual Power Plant (VPP). This network connects homes with solar and battery systems to act as a single power plant, helping to stabilise the grid during periods of high demand. By allowing Tesla to manage your Powerwall, it will automatically charge your battery when most profitable and discharge to the grid when needed, all without affecting your day-to-day life.
Tesla or Fox Ess: App Monitoring
Both Tesla and Fox ESS provide intuitive mobile apps that make monitoring your solar and battery system simple and accessible from anywhere. The Tesla app is highly polished, offering real-time insights into solar generation, battery charge levels, home consumption, and grid usage, all in a sleek, user-friendly interface. It also integrates seamlessly with other Tesla products, such as EVs and their EV Charger the Wall Connector, giving you a single platform to manage your entire energy ecosystem. Rated 4.1 stars from 1.4k users, ranking #32 in Lifestyle overall, the reviews speak for themselves.
In comparison, the Fox ESS Cloud app is simple yet powerful, giving homeowners the ability to monitor, manage, and optimise their system. However, unlike Tesla’s app, which is widely praised for its premium design and seamless integration, the Fox ESS app has faced criticism, holding a modest 2.1-star rating on the Apple Store from just 199 users. That said, with the release of version 2.0 and AI-powered optimisation features on the horizon, Fox ESS appears to be addressing these shortcomings and investing more heavily in its software.
Both apps support Time-Based control, enabling users to manage their energy tariffs, and decide when to buy and sell electricity to and from the Grid. This functionality can be optimised to help balance the grid and maximise savings, as both batteries are compatible with Octopus Energy. This means that customers can unlock low-cost green energy, fully automated by the Kraken platform.
Fox Forrest
A nice addition to the FoxCloud 2.0 is Fox Forest. Launched on July 22nd 2024, Fox Forest allows system owners to earn “carbon value” by monitoring their home energy consumption and solar generation through the FoxCloud app. This carbon value can then be used to plant trees in a reforestation project located in Tanzania’s Southern Highlands. Users can track their tree’s progress and contribution to a greener future. By participating in Fox Forest, you’ll be actively contributing to reforestation efforts and combating climate change.
Back up Power
The Tesla Powerwall 3 offers full home backup, ensuring a seamless switch from grid supply to solar and storage during an outage via the Tesla Gateway. The first Tesla Backup Gateway launched in the US in late 2016, with the Backup Gateway 2 rolling out for Europe in early 2019.
New to the Fox ESS product line in 2025, the EPS Backup Box is compatible with the Fox ESS battery range. It automatically switches between on-grid and off-grid modes, keeping essential, or even all household circuits, powered without interruption, and is designed to rival other solar gateways on the market.
While Tesla offers a more mature, time-tested solution, both systems provide the same peace of mind: your home stays powered, no matter what.
Tesla’s Storm Watch
With the Tesla Powerwall 3 you can also adjust your Backup Reserve percentage, to control how much energy your Powerwall system has readily available in the event of a power outage, disconnect your Powerwall from the grid to simulate a grid outage, and utilise Tesla’ Storm Watch feature to be prepared for upcoming severe weather. With the Tesla Powerwall 3, homeowners can adjust their backup reserve percentage to control how much energy they have stored ready for an outage, simulate a grid failure to test backup performance, and take advantage of Tesla’s Storm Watch feature to prepare for severe weather.
Storm Watch has made the Powerwall especially popular in regions prone to hurricanes or tornadoes, as it automatically responds to local storm alerts by fully charging the your Tesla battery in advance. This ensures households are best prepared for potential blackouts.
While Fox ESS is developing an AI-powered optimisation feature that will analyse usage patterns and weather data to maximise efficiency, when it comes to reliable backup power, Tesla remains the tried, tested, and a proven pioneer.
Safety Features
Tesla Powerwall 3 Saftey Features
- Arc Fault Circuit Interrupter (AFCI)
- Rapid Shutdown (RSD)
- Fitted with a Mid-Circuit Interrupter (MCI) Solar Shutdown Device.
- Thermal Monitoring and Management
- Integrated Switch Locking Mechanism
- Ground Fault Protection
- Built-in Protective Earth Impedance Check
Fox ESS EVO Safety Features
- Active Fire Suppression
- Insulation Monitoring
- Residual Current Monitoring
- DC Reverse Polarity Protection
- Anti-Islanding Protection
- AC Short-circuit Protection
- AC Overcurrent/ Overvoltage Protection
- DC Switch
- AFCI Protection
- Overvoltage DC: Type II /AC: Type II
The Final Verdict on Tesla Powerwall 3 or the Fox ESS EVO Battery
Key reasons why you should choose the Powerwall 3
- A reputable brand you can trust, with proven product maturity, long-term industry presence, and a solid warranty that even covers unlimited cycles.
- Easily expandable with dedicated expansion packs already available, flexible inverter settings, and greater usable capacity per unit.
- An advanced, highly rated, and widely recommended app.
- Your interested in being a part of a global network and brand, giving you access to exclusive tariffs and benefits.
Key reasons why you should choose the Fox ESS EVO Battery
- A cost-friendly solution without compromise. Enjoy the same premium look and feel at a more affordable initial price, paying only for the hardware you truly need.
- Built-in fire suppression for added peace of mind, especially for indoor installations.
- Offers a faster charge rate, ideal for homeowners looking to optimise on Time-of-Use tariffs, and with a higher round-trip efficiency, you can store and reclaim more of your energy.
- With a superior IP rating, the Fox ESS EPS Backup Box is fully suitable for outdoor installation.
Choosing between the Tesla Powerwall 3 and the Fox ESS EVO Battery ultimately depends on your budget, capacity needs, future plans and perhaps your political views.
The Tesla Powerwall 3 is a premium, all-in-one energy storage solution with over a decade of development. It is tried, tested, and highly scalable, offering more storage per unit, though this also makes it heavier and slightly more challenging to manoeuvre. Tesla excels in software, integration, and community. As a globally recognised pioneer, Tesla has set the standard for home energy storage, and if you already own or plan to purchase a Tesla EV, the choice is almost seamless.
The Fox ESS EVO Battery, while from a younger and less established company, delivers strong performance at a more affordable price. Its app may not yet match Tesla’s polished platform, but the battery itself provides a credible, cost-effective alternative to the Powerwall 3. Even providing some notable enhancements, such as the better charge rate, built-in fire suppression safety feature and superior gateway IP rating.
Both the Tesla Powerwall 3 and Fox ESS EVO Battery are excellent choices for homeowners aiming to reduce grid reliance and cut energy costs. Not sure whether the Tesla Powerwall 3 or Fox ESS EVO battery is right for you? Contact our team on 01322 479369 or click ‘Enquire Now’ to discuss all things solar and storage with one of our energy advisors.
