Fox ESS Battery Review: An Independent Assessment by Solar Choice

Note: Solar Choice is not affiliated with Fox ESS or any other battery manufacturer. Our reviews are independently written using technical documentation and industry analysis.

At a Glance: Fox ESS Batteries score 2.1 out of 5

Scoring is based on our solar battery scorecard, which is consistently applied to each brand and battery available on the Australian market. This scoring reflects Fox ESS’s residential battery systems including the EQ and EP series.

$ Price: Based on data from Solar Choice’s network of solar installers, the average price for an installed Fox ESS battery is $832 per usable kWh. This makes it one of the lowest-cost options available.

  • Company Backing and Trustworthiness (2 out of 5): Fox ESS entered the Australian market around 2021. The company has established an office in Victoria with a small local support team.
  • Warranty Offer (3.5 out of 5): Fox ESS batteries come with a throughput warranty of 3.7MWh to 4.1MWh per usable kWh, a 10-year product warranty, and a minimum capacity rating of 70% at the end of the warranty period. The throughput warranty offered is above average.
  • Customer Reviews (1 out of 5): Based on verified customer reviews, Fox ESS holds an average rating of 3.17 from 7 reviews on Solar Choice’s independent platform. This mixed feedback results in a low score.
  • Functionality (2 out of 5): Fox ESS batteries are IP65 rated for outdoor use and support modular stacking. However, they lack AC coupling without buying an additional hybrid inverter, built-in fire suppression, and independent module-level balancing, meaning new batteries may be impacted by older ones in an expanded system. These limitations reduce long-term flexibility and safety features.

Please note that this score and review reflects our opinion only and we encourage readers to do their own research.

Overview of Fox ESS – Company History

Fox ESS is a Chinese energy technology manufacturer specialising in solar inverters, energy storage systems, and EV charging solutions. The company is a subsidiary of Tsingshan Group, one of the largest stainless steel manufacturers globally, which has helped Fox ESS scale its operations across Asia, Europe, and Oceania.

Fox ESS first launched in Australia in 2021, initially selling their solar inverter products. Their first battery was approved by the Clean Energy Council in 2022, meaning they are a relatively new-entrant to the solar and battery market. Fox ESS have now listed there local office in Springvale, Melbourne on their Australian website.

Fox ESS Battery Range and Options

Fox ESS provides a range of high-voltage, stackable lithium iron phosphate (LiFePO4) battery systems under the EQ and EP series which are both approved by the Clean Energy Council. These batteries are typically designed to integrate with Fox hybrid inverters, although some limited compatibility with third-party systems exists.

EQ Series (DC-Coupled, Stackable System)

Fox ESS ECS stackable Battery image

The EQ series is Fox’s main high-voltage modular battery platform. Each system consists of a CM (control module) and between 2–9 battery modules, each with a capacity of 4.66kWh. That means the solution can scale to just under 42kWh in one stack.

  • DC-Coupled: Must be paired with a compatible Fox ESS hybrid inverter
  • Depth of discharge: 100%
  • Ingress protection: IP65, suitable for indoor/outdoor installations
  • Cooling: Natural convection (fan-free)

Expansion is possible, but the warranty requires new modules to be within 0.5V of existing modules and recharged within the past 5 months, making post-installation upgrades technically feasible but logistically complex.

The batteries must be paired with a compatible Fox-ESS inverter and they have recently broadened their range of hybrid inverters up to 10kWh single-phase.

EP Series (DC-coupled, Fixed Units)

Fox ESS EP5 Battery image

The EP series includes fixed-capacity wall-mounted batteries that combine battery modules and the battery management system (BMS) in a single enclosure.

  • Key models: EP5 (5.18kWh), EP11 (10.36kWh) usable capacity
  • DC-coupled: Must be paired with a compatible Fox ESS hybrid inverter
  • DOD: 90%
  • Operating range: -10°C to +55°C

The EP series may appeal to installers seeking simpler, space-saving systems. The EP Series is expandable by adding additional units in parallel which will require an additional junction box. This is a most costly and space-consuming approach than the stackable ECS series.

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How Much Does a Fox ESS Battery Cost?

Fox ESS batteries are among the most affordable on the Australian market. Based on data from Solar Choice’s installer network, the average installed cost is $832 per usable kWh, excluding rebates.

For example:

  • A 10.4kWh EP11 system may cost $8,650–$9,200 installed
  • A 17.3kWh ECS2900-H6 stack might cost $14,000–$15,500 installed

As Fox ESS batteries are DC-coupled, homeowners would also need to buy a compatible Fox ESS hybrid inverter to connect the system. Fox ESS batteries are most likely to be used when installing solar and batteries for the first time to avoid duplicating the inverter.

Fox ESS systems are eligible for the federal battery rebate, which could reduce the net cost by up to 30%, depending on your state and VPP eligibility.

Fox ESS’s Warranty Offer For Australian Customers

Fox ESS offers a 10-year product and performance warranty for its ECS and EP series batteries. The performance warranty guarantees that the battery will have a minimum of 70% of its original usable capacity after 10 years, or will have throughput a minimum amount as laid out in the below table:

ProductNominal Energy (kWh)Usable Energy (kWh)Minimum Throughput (MWh)Throughput per usable kWh
EP1110.3610.3638.43.71 MWh
EQ4800 (4 x battery modules)18.6418.6478.644.21 MWh

Fox ESS’s warranty terms include typical exclusions like improper installation and use. Fox ESS now have a listed office in Australia to support local customers with technical issues and warranty claims.

See attached full warranty policy for Fox ESS batteries.

Fox ESS Battery Technical Specifications Table

FeatureEQ4800 L4 (18.64kWh)EP11 (10.4kWh)
Battery ChemistryLiFePO4LiFePO4
Usable Capacity (kWh)18.6410.36
ScalabilityModular (up to 42kWh)Fixed
Depth of Discharge (DOD)100%90%
Max Discharge Power (kW)Depends on inverter (up to 10kW single phase)Depends on inverter (up to 10kW single phase)
Round Trip Efficiency>95%>95%
IP RatingIP65IP65
Cooling MethodNatural ConvectionNatural Convection
InstallationStackable, floor mountedWall-mounted
Minimum Throughput4.1MWh per usable kWh3.7MWh per usable kWh
Operating Temperature (°C)-10 to 55°C-10 to 55°C

Pros and Cons of Fox ESS Batteries

ProsCons
✓ Competitive installed pricing (<$850/kWh installed)✗ Limited public performance data or long-term Australian track record
✓ IP65 rated for outdoor/sheltered installs✗ Expansion requires SOC and voltage matching — not truly plug-and-play
✓ Modular design for ECS makes it flexible✗ Must use Fox inverters — limited third-party compatibility
✗ Low number of customer reviews with mixed feedback

Conclusion: Our Verdict On Fox ESS Batteries

Fox ESS as a new entrant to the market have an aggressive pricing strategy which they hope to win market share. Their batteries are scalable up to over 40kWh and can now be linked with their expanded range of single and three phase hybrid inverters with up to 10.5kW capacity for single-phase installations.

The warranty terms on face value look competitive or better than some of the bigger brands offering greater minimum throughput than most brands on the market.

With the short company history and low number of customer reviews, the longevity and reliability of the Fox ESS batteries largely remains to be seen.

Read more product reviews from Solar Choice

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Jeff Sykes
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Reviews from Australians who have installed Fox-ESS Batteries

Rated 3.38 from 8 reviews
5 star
4
4 star
1
3 star
0
2 star
0
1 star
3

Showing 8 of 8 Reviews

15th September 2025
Ann
-

Review left 1 year after system installed

5.00

I am happy with my battery even though I don't know the brand.

9th September 2025
Fan
-
5.00

Fox ESS's 42kWh battery storage giving me so much safe. Their tech support was amazing too.

10th August 2025
Andrew
-
1.00

Installers have been back 4 times, system still does not seem to be operating correctly, getting huge electricity bills and power outages. Use a reputable business not Arise Solar.

1st August 2023
Linda
NT - 0870
6kW system
5.00

So far so good. Only just had it installed.

10th September 2025
Andrew
-
1.00

27th August 2025
Belinda
-
6kW system
4.00

25th June 2025
Peter
-
1.00

3rd March 2025
Brynlee
-
7kW system

Review left 6 years after system installed

5.00

Showing 8 of 8 Reviews