Fox ESS EP11 (global datasheet v1.5, 24 November 2025)

By Daan Haket · researched and written with an AI assistant · updated 26 October 2026

EP11 is a high-voltage battery, rather than a complete AC power system. Start with the inverter and the exact EP11 datasheet version: the global and Australian documents do not state the same depth of discharge.

Research from manufacturer documents, not a hands-on test. Values and missing details are kept separate below.

What matters on your quote

The global v1.5 sheet gives nominal energy and depth of discharge, but no separately labelled usable-kWh figure or battery power in kW. We do not multiply voltage by maximum current, or nominal energy by depth of discharge, and present the result as a manufacturer specification.

• The Australian EP11 document lists 100% depth of discharge; the global v1.5 sheet lists 90%. Do not combine them in one specification.
• The EU warranty is framed through professional purchasers/installers. Ask your installer to identify the UK end-user claim route and provide the applicable document.
• Check both the inverter’s AC output and the battery charging limit. The pack’s quoted efficiency excludes losses elsewhere in the installation.

At a glance

Not in the documents we checked so far: usable capacity, continuous / rated power (original units and basis), peak power, coupling, backup power, UK list price.

Ask the installer before you sign

• Is the usable capacity on the quote the figure above, or a nominal one?
• Can it charge fast enough to fill in your cheap window? Charging power × hours of the window is the most it can take in.
• Is any equipment needed for backup in a power cut included in the price?
• Does it work alongside your current solar inverter, or replace it?
• Which warranty conditions apply in the UK, and what do you have to do to keep them?

Will it pay back for you?

Try it in the calculator →

Usable system capacity is not established here, so the calculator opens without a battery-capacity preset. Enter the usable capacity from your installer’s quote. Add your own installed price and tariff. If the datasheet does not state a round-trip efficiency, use your installer’s figure.