Picture a Crawley mid-terrace with no garage and no side passage. Where would a home battery go? In a town where terraced houses are the largest housing type, 37.4% of 45,500 households at the 2021 Census, the honest answer depends more on each manufacturer’s ratings than on its brochure. This guide works through that question for five brands, across the three Sussex towns we cover: EnSmart batteries in Sussex, Tesla Powerwall, Sigenergy SigenStor, EcoFlow PowerOcean and Fox ESS.
Before the detail, the plain position. The battery systems in HCE’s own job photos are EnSmart, and EnSmart is the range we fit. For any other brand, ask us and we will confirm in writing how it would be supplied, who installs and commissions it, and what warranty attaches. No brand is ranked here, and no prices are given. The county overview is on solar panels in Sussex, and sizing in general on our battery storage page.
Indoor, outdoor or either: what the ratings say
An ingress-protection (IP) rating tells you how well a unit is sealed against dust and water, and it decides more Sussex siting conversations than anything else.
| Brand | Battery rating | Inverter or controller | Mounting |
|---|---|---|---|
| EnSmart | ELV-W wall pack IP50, indoor only; ELV-F floor packs IP55, outdoors away from direct sunlight | SolarAll-H IP65, indoor or outdoor | Wall pack or floor pack |
| Tesla Powerwall 3 | IP55 enclosure, IP67 on battery and power electronics | Built into the unit | Floor or wall |
| Sigenergy SigenStor | IP66 | IP66 controller on top of the stack | Floor-standing or wall-mounted |
| EcoFlow PowerOcean | IP65, with built-in heating pads | Hybrid inverter in the system | Wall or floor |
| Fox ESS | EP5 IP65, indoor or outdoor | H1-G2 IP65, wall-mounted | EP5 wall or floor |
Size and weight, where the manufacturer publishes it
Ratings say where a unit may go; size and weight say whether it will get there. A Powerwall 3 is 1105 × 609 × 193 mm and 130 kg, a two-person lift through a terraced hallway. A Sigenergy module is 767 mm wide, 270 mm tall and 265 mm deep, at 62 kg (6.02 kWh) or 78 kg (9.04 kWh), with the controller adding 18 kg on the smaller single-phase models. Fox ESS gives the EP5 as 380 × 625 × 147 mm and about 50.5 kg, and the H1-G2 inverter as 434 × 418 × 185 mm and 22 kg. EnSmart and EcoFlow publish no pack weight or dimensions in the sources behind our product pages, so we measure those at survey rather than guess.
Three towns, three siting problems
Crawley. Designated a New Town on 9 January 1947, it has 25.1% of households in flats or maisonettes and 14.2% in detached houses. In a terrace the choice is usually an understairs cupboard, which suits EnSmart’s indoor ELV-W pack, or a rear wall, where the outdoor-rated units come in. Fox ESS’s warranty asks for 300 mm of clearance around the pack, so a narrow rear wall needs measuring. With 22.9% of Crawley households renting from a social landlord, the landlord’s agreement often comes before any of it.
Horsham. The district’s 37.2% detached and 26.9% semi-detached households usually have a garage or utility room, which keeps an indoor-only pack simple and gives a heavier floor-standing stack somewhere to stand. Horsham’s historic core around the Causeway is a conservation area: keep any outdoor unit off the street-facing side and speak to Horsham District Council first if the house is listed.
Haywards Heath. The civil parish has 3,600 purpose-built flats, 27.3% of its homes. UK Power Networks needs the building owner’s permission before storage work on a multi-occupied building, so the freeholder or managing agent decides first, whichever brand you prefer.
One network across all three towns
The town centres of Horsham, Crawley and Haywards Heath all sit in UK Power Networks’ South Eastern Power Networks area, with Horsham’s about 2.9 km from SSEN’s boundary, so western addresses are worth checking by postcode. Equipment up to 16 A per phase (3.68 kW) is notified within 28 days of commissioning under G98, and larger systems need G99 approval first. UK Power Networks approves automatically where the maximum export after any export limitation is under 5 kW. On the published line-ups, Sigenergy’s 3.6 kW controller (16.0 A) and Fox ESS’s 3.7 kW H1-G2 (listed at 3,680 VA) sit on the G98 line; EnSmart’s 3–6 kW SolarAll-H and Tesla’s 3.68–11.04 kW settings straddle it; EcoFlow’s 6 kW single-phase off-grid output is above it. Ofgem’s 2024/25 figures for South Eastern Power Networks show about 42.2 interruptions per 100 customers and 30.4 minutes lost per customer, down from 49.5 and 36.5 the year before.
A Horsham June and a Sussex December
PVGIS gives the three towns a similar winter, about 139 to 146 kWh in December for a 4 kWp south-facing array, but different summers: about 493 kWh in June at Crawley, 503 kWh at Horsham and 526 kWh at Haywards Heath. On our arithmetic a Horsham roof makes about 16.8 kWh on an average June day and about 4.5 kWh in December. The December day fits inside the smallest published step of all five brands, from EcoFlow’s 5 kWh pack to Tesla’s 13.5 kWh unit. So the siting decision and the sizing decision are separate: find the place first, then size to the evening.
Conditions that follow the battery to its spot
Where a battery sits can affect its warranty. Fox ESS’s battery cover can be voided by less than 300 mm of clearance or poor ventilation. Sigenergy’s warranty recommends 10–30°C for battery life. EcoFlow’s 15-year warranty, to 70% of original capacity, depends on registration and correct installation. Tesla’s ten years applies to a Powerwall bought from Tesla or a Tesla certified installer. For EnSmart, the ELV-W datasheet lists a five-year product and ten-year performance warranty, and we confirm the exact terms in writing. None of the five provides backup in a power cut unless the installation is designed and wired for it.
The kit in our photos
The cabinets in our job photos are EnSmart SolarAll, the range we fit. For local figures, see battery storage in Crawley, Horsham and Haywards Heath. Ask for a Sussex survey, or call 0204 547 1892.
Sources: EnSmart SolarAll-H and ELV datasheets as cited on our EnSmart product page; Tesla Powerwall 3 UK datasheet (2026) and Tesla Powerwall Warranty, European Warranty Region, Rev. 1.16; Sigenergy Battery 6.0/10.0 and Energy Controller (version 20260330) datasheets and Europe warranty (27 May 2025); EcoFlow UK PowerOcean product pages; Fox ESS EP5 datasheet V1.5, H1-G2 datasheet V2.0 and UK battery warranty policy V4.5; ONS Census 2021, TS044 Accommodation type and TS054 Tenure (Nomis; censusdata.uk for Haywards Heath civil parish); PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023), runs of 15 October 2026; UK Power Networks licence boundaries (December 2024) and Solar and storage: cost, time and what’s involved (read 15 October 2026); NESO GB DNO licence areas (May 2024); Energy Networks Association EREC G98 Issue 2 (10 March 2025); Ofgem, RIIO-2 Electricity Distribution annual report 2024 to 2025, supplementary datafile.