Fogstar Energy 16.1kWh Battery: Specs, Stacking and Price Position

The Fogstar Energy 16.1kWh battery is a lithium iron phosphate storage module sold as the building block of a modular stack system: one module gives 16.1kWh, two give 32.2kWh and four give 64.4kWh within a single stack¹. It is built around 16 Grade A EVE MB31 cells of 314Ah in a 16S1P configuration, managed by a 200A PACE battery management system, and housed in a sealed IP65 enclosure that can be installed indoors or outdoors³. The IP65-rated 16.1kWh battery is listed from £1,999.99, which Fogstar's own deep-dive page equates to £161.49 per kWh¹.

There are several versions of the 16.1kWh product, and the differences matter when comparing prices and warranty terms. The ECO 48V version is listed at £1,949.99, stated as £121.12 per kWh⁵. The IP65-rated modular battery stack version is listed at £2,499.99 and was on pre-order in September 2026, with the next batch arriving in December⁶. A separate expansion module, for adding capacity to an existing stack, is listed at £2,049.99⁷. All of these are maker prices for the hardware alone: installation is quoted separately, and the VAT position is not stated on the listings.

The 16.1kWh battery at a glance

Fogstar Energy is the home-storage arm of Fogstar, a UK company founded in 2016 to supply lithium-ion cells to the UK market, which partnered with EVE Energy in 2021 and launched its first 15kWh home battery in 2024. The 16.1kWh battery is the current core product, described by Fogstar as UK-designed⁴. It exists in an ECO form, an IP65-rated form and as expansion modules for the modular stack system, and the same 16.1kWh module appears inside the 32.2kWh and 64.4kWh stacks⁵.

What distinguishes the product at this capacity is the combination of price and modularity. At £161.49 per kWh as stated by the maker, it sits well below the per-kWh cost of most all-in-one home batteries, though the buyer supplies or bundles the inverter separately⁴. The trade-off is weight and installation: the IP65 modular stack weighs 148kg, and Fogstar's wall-mount page refers to the battery's significant weight of 140kg and states that professional installation by a qualified contractor or structural engineer is needed¹³. For context on where modular systems sit against all-in-one units, see modular and stackable home batteries and all-in-one battery systems.

Specifications: 16.1kWh usable, 314Ah cells, 48V nominal

The headline specification is 16.1kWh of usable lithium battery storage per module, at a nominal voltage Fogstar lists as 48V on the battery and bundle pages and 51.2V on the ECO product page and in a company case study³. The two figures describe the same 16S1P cell arrangement: 16 cells of 3.2V in series give 51.2V, which the range is marketed under as a 48V system. Capacity is given as 314Ah⁵.

The discharge current difference is worth noting when sizing: the 16.1kWh 48V battery is listed with up to 200A discharge current for high-demand applications, while the IP65 modular stack is listed at 150A maximum³. How that translates into kilowatts of output is covered in battery power ratings. The ECO battery's dimensions, just under 900mm tall, mean floor space rather than wall space is what a household needs to plan for⁵.

Chemistry and cycle life: LiFePO4 rated to 8,000 cycles

The battery uses premium Grade A EVE MB31 LiFePO4 cells, 16 of them at 314Ah, which Fogstar describes as fully matched and balanced³. Lithium iron phosphate is the chemistry most home battery makers now use for stationary storage because of its thermal stability and cycle tolerance; the chemistry itself is explained in home battery chemistries.

Fogstar rates the battery at 8,000 cycles at 91% depth of discharge, a figure stated consistently across the expansion module, the IP65 modular stack, the ECO battery and the 64.4kWh stack⁶. The ECO page adds the test conditions: 8,000 cycles at 25°C with 50A charge and discharge current⁵. That figure is at the optimistic end of what is claimed for LiFePO4 generally. Guidance from other makers in the UK market gives LFP cells delivering over 6,000 full charge cycles, and cells rated for 6,000 cycles running daily for well over a decade before capacity drops off¹⁶. The figures differ because cycle life depends on discharge depth, current and temperature, and Fogstar's 8,000-cycle rating is tied to specific test conditions rather than a guarantee of service life. What a household should take from the range is that the chemistry is durable, and that the real determinant of lifespan is how deeply and how fast the battery is worked, as covered in cycle life and degradation.

Price position: from £1,999.99, roughly £161 per kWh

Fogstar's published prices, read in September 2026, are maker list prices for the hardware only:

Two things position this product in the UK market. First, the per-kWh figures are low: £161.49 per kWh on the maker's own deep-dive page, and £121.12 per kWh on the ECO version⁴. Second, the price does not include an inverter or installation. Bundles change that: a 16.1kWh battery with inverter bundle is listed at £2,909.03, down from an original price of £3,161.99, and bundle collections start from £2,564.95 for the ECO 16.1kWh, from £2,610.95 for the IP65 version and from £3,990.95 for a 32kWh setup³. The VAT position is not stated on these listings, so they should be read as quoted prices rather than confirmed VAT-inclusive figures. Wider cost context, including installation, is in how much a home battery costs.

Warranty and support: the terms differ by version

The warranty position needs care, because Fogstar's own pages give different terms for different versions of the same capacity. The 16.1kWh 48V battery page states a 10-year warranty³, and the company's battery comparison blog also lists a 10-year warranty for the IP65-rated 16.1kWh battery⁸. The modular stack pages state something shorter: a 6-year warranty with 10 years of UK-based customer service support, a formula repeated on the IP65 modular stack, the ECO battery, the expansion module, the 32.2kWh stack and the 64.4kWh stack⁶.

The consistent element across the range is the 10 years of UK-based customer service support, which is a support commitment rather than a warranty term⁶. What the warranty does and does not cover, and how battery warranties generally handle retained capacity and throughput, is explained in home battery warranties.

Fire safety, warmth and the IP65 rated casing

The 2026 versions of the battery add two features that earlier home batteries often lacked: integrated fire suppression and heating. The IP65 modular stack carries a built-in, heat-activated aerosol fire suppression system, described as providing fast, automatic internal protection with no ongoing maintenance, and the 16.1kWh 48V battery likewise lists an integrated automatic fire suppression system¹³. Fogstar's comparison blog lists fire suppression and heating alongside the 10-year warranty as defining features of the IP65-rated battery, with additional 2A JK balancing support⁸.

Heating matters for a UK outdoor installation. The IP65 stack's working temperatures are listed as 0 to 45°C for charging, with heating, and minus 20 to 45°C for discharge⁶. The enclosure itself is fully sealed and IP65-rated, allowing both indoor and outdoor installation, and the 16.1kWh 48V battery adds integrated wheels for easier installation and maintenance³. IP65 means the enclosure is protected against dust and water jets, which is what makes outdoor siting possible; where a battery can legally and safely be placed is covered in battery siting and location and home battery fire safety.

Stacking from 16.1kWh to 64.4kWh

The modular stack system is the product's main selling point. It starts at 16.1kWh using a single battery module and control panel, and can be expanded up to 64.4kWh within a single stack⁸. Each 32.2kWh stack is built from two 16.1kWh modules, and each 64.4kWh stack from four¹¹. Beyond a single stack, up to 16 stacks can be connected together, which Fogstar describes as delivering over 1MWh of energy storage capacity, a scale aimed at commercial rather than domestic use⁸.

Expansion is designed to be phased: additional stacks can be added at any stage for growing energy requirements, and the 32.2kWh modular stack is described as expandable up to 64.4kWh with additional stacks¹⁰. The expansion module has conditions, though. It is intended for use only with compatible Fogstar Energy modular battery stack systems already fitted with a stack control unit, LCD touchscreen interface, battery base plate and main breaker assembly⁷. In other words, a household cannot buy the cheaper expansion module as a first unit: the first purchase has to be a stack with its control unit. Sizing a first stack against actual household consumption is covered in what size home battery you need and adding more batteries later.

Availability is the practical constraint. The 16.1kWh, 32.2kWh and 64.4kWh IP65 stacks were all listed on pre-order in September 2026, with the next available batch arriving in December, which Fogstar attributes to exceptionally high demand, adding that orders placed before the update ship as scheduled⁶.

Inverter compatibility and monitoring: PACE BMS and the touchscreen

The battery is managed by a 200A PACE battery management system, which Fogstar describes as allowing seamless plug-and-play compatibility with popular inverters³. The 16.1kWh 48V battery page lists compatibility with Luxpower, Victron, Sunsynk, Solis, Growatt, Sofar, Goodwe and many other leading inverter brands; the IP65 modular stack page names Victron, LuxPower, Sunsynk, Solis, Voltronic, Voltacon and more, with CAN and RS485 communication enabling the integration³. The ECO battery comes with pre-loaded compatibility for Victron, Sunsynk, Solis, Luxpower and Voltacon⁵.

Monitoring is local rather than app-based. Each unit carries a 4.3-inch TFT LCD touchscreen for monitoring and inverter protocol selection, and the stack pages describe the touchscreen as providing real-time system data, diagnostics and control³. Protocol selection on the screen is how the battery is matched to the inverter brand, which is what makes the same module work across Victron, Sunsynk and Solis systems without a separate configuration tool. What a BMS does in a home battery, and the difference between local and app monitoring, is covered in battery management systems and battery monitoring.

How the 16.1kWh battery supports a home's self sufficiency

A 16.1kWh battery is a substantial store by domestic standards: enough to run an average home's overnight consumption and to shift a full day of solar generation from afternoon to evening, and the modular design means the household, not the supplier, decides when to add capacity. Fogstar's own case study material shows the 16.1kWh batteries in use for home backup and off-peak energy savings, which is the practical independence case: charging on a cheap overnight tariff and discharging through the evening peak¹⁵. The tariff-stacking side of that is covered in batteries and smart tariffs.

The dependencies that remain are worth stating plainly. The battery stores energy but does not generate it, so the home still needs the grid, a solar array or both to fill it. The inverter is a separate purchase, and the choice of inverter brand determines the ecosystem of monitoring and support the household lives with. The warranty and support route runs through Fogstar as a UK company, which shortens the chain compared with an importer, but it is still a single company's commitment, and the current pre-order wait for the modular stacks shows what dependence on one supplier's production schedule looks like. For the wider picture of what a battery does and does not free a household from, see home batteries and energy independence, and for the rest of the Fogstar range, Fogstar Energy home batteries.