Across the four Hampshire councils our towns sit in, privately kept plug-in vehicles rose from about 12,452 to 17,497 in the year to June 2026, about 40% (our sum and arithmetic on DVLA figures). A car charger and a home battery share one supply and one network operator, so in Hampshire it pays to compare battery brands from the grid side first. This guide does that for EnSmart batteries in Hampshire, Tesla Powerwall, Sigenergy SigenStor, EcoFlow PowerOcean and Fox ESS, on the manufacturers’ published figures.
To be clear about our own position: the battery systems in HCE’s own job photos are EnSmart, and EnSmart is what we install. For Tesla, Sigenergy, EcoFlow or Fox ESS, ask us and we will confirm in writing how it would be supplied, who installs and commissions it, and what warranty attaches. Nothing here is a ranking or a price. The county picture is on solar panels in Hampshire, and the general sizing guide on battery storage.
One operator, one set of rules
Every town centre we cover, from Farnborough and Fleet to Basingstoke, Aldershot, Alton and Petersfield, sits in SSEN’s Southern Electric Power Distribution area. Basingstoke’s is about 27.1 km inside it; Farnborough’s is about 3.4 km from UK Power Networks’ boundary, so addresses on that side are worth a postcode check. The thresholds come from the Energy Networks Association: equipment up to 16 A per phase, 3.68 kW on a single-phase supply, is notified within 28 days of commissioning under G98. Above that, a G99 application must be approved before work starts. SSEN says it aims to answer fast-track applications within 10 working days. Existing panels on the roof count towards the total for the property.
Where each inverter sits against the G98 line
| Brand | Published single-phase sizes | At or under 3.68 kW? | Three-phase option |
|---|---|---|---|
| EnSmart SolarAll-H | 3–6 kW | Smaller sizes; we check the ENA type-test register entry | 10–20 kW series |
| Tesla Powerwall 3 | Output set from 3.68 kW to 11.04 kW | At the 3.68 kW setting | Unit is single-phase; Backup Gateway 2 supports three-phase feed-in |
| Sigenergy Energy Controller | 3.0–12.0 kW | 3.0 and 3.6 kW (16.0 A) | 5.0–30.0 kW |
| EcoFlow PowerOcean | 6 kW continuous off-grid output | Depends on set-up and export limit; ask | Up to 12 kW backup output |
| Fox ESS H1-G2 | 3.0, 3.7, 4.6, 5.0, 6.0 kW | 3.7 kW, listed at 3,680 VA | KH series 7–10.5 kW for larger homes |
The practical reading is that the inverter size, more than the battery, decides whether a job waits for SSEN. A larger inverter is not wrong. It charges and discharges faster, which can suit a big evening load. It simply moves the start date to after the approval.
If an electric car is on the way
Basingstoke and Deane alone went from about 4,382 to 6,203 privately kept plug-in vehicles in that year, and Hart counts about 4,111. In Rushmoor, home to Farnborough and Aldershot, most plug-in registrations are company vehicles, so only its 2,201 privately kept are a household figure. The brands handle growth differently. EnSmart, Sigenergy, EcoFlow and Fox ESS are modular, adding packs or modules of 5.12, 6.02 or 9.04, 5 and 5.18 kWh respectively. Tesla adds 13.5 kWh Expansion units. Sigenergy offers an optional DC charging module at 12.5 or 25 kW over CCS2, with a 3-year warranty against the battery’s ten. The EV charger in our own job photos is EnSmart’s SmartBee-M, a 7 kW unit rated IP65 with OCPP 1.6. Whichever way you go, the survey checks the main fuse before anything is specified.
Backup is a design decision with every brand
Ofgem’s 2024/25 figures for Southern Electric Power Distribution show about 41.8 supply interruptions per 100 customers, inside its target of 46.1, and about 51.2 minutes lost per customer, above its target of 41.7. Those are licence-area averages, not a forecast for your street. No battery here keeps the lights on by default. Tesla’s non-backup configuration gives no backup at all; with a Backup Gateway 2 it can run the whole house or chosen circuits. Sigenergy’s original SigenStor needs the separate Sigen Energy Gateway. Fox ESS’s EPS output switches in under 10 milliseconds but is limited to the inverter’s rating. EcoFlow publishes 6 kW of continuous off-grid power on single-phase. EnSmart lists a UPS function with a 10-millisecond switchover for backup-designed systems. Each needs its own design and wiring.
Fleet garages, Rushmoor terraces and Petersfield’s park
The housing changes the siting more than the brand. In Fleet’s three wards 45.4% of households live in detached houses and 73.7% own their home, so a garage usually takes any of the five. Rushmoor is 32.1% semis, 23.5% terraces and 23.2% purpose-built flats, so outdoor-rated units matter more: Tesla’s IP55 enclosure, Sigenergy’s IP66, and IP65 on the EcoFlow and Fox ESS units, while EnSmart’s IP50 wall pack stays indoors. Petersfield lies wholly inside the South Downs National Park, and the National Park Authority is the planning authority there. A battery in a garage changes nothing outside; one on an outside wall in The Square conservation area, or on a listed building, is worth checking with the Authority first.
Warranty terms, briefly
EnSmart’s ELV-W datasheet lists a five-year product and ten-year performance warranty, and we confirm the exact terms in writing. Tesla gives ten years, with 80% retained for UK installations, on a Powerwall bought from Tesla or a Tesla certified installer. Sigenergy gives a 10-year limited warranty to 60% usable energy or a throughput cap. EcoFlow publishes 15 years of daily use to 70% of original capacity. Fox ESS gives ten years on EP-series batteries, and on the inverter only with the Fox Cloud connection.
Sizing against a Hampshire roof
PVGIS gives a 4 kWp south-facing array about 136 kWh in December at Basingstoke and 139 kWh at Fleet and Petersfield, and about 482 kWh (Fleet and Aldershot) to 506 kWh (Petersfield) in June. That is about 4.4 to 4.5 kWh a day in December and 16.1 to 16.9 kWh in June, on our arithmetic. For local detail, see battery storage in Basingstoke, Fleet and Petersfield. Ask for a Hampshire survey, or call 0204 547 1892.
Sources: EnSmart SolarAll-H and ELV datasheets and SmartBee-M distributor listing, 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, Energy Controller (version 20260330) and EV DC Charging Module datasheets and Europe warranty (27 May 2025); EcoFlow UK PowerOcean product pages; Fox ESS H1-G2 datasheet V2.0, UK battery warranty policy V4.5 and inverter warranty policy V2.3; DfT and DVLA, VEH0142 licensed plug-in vehicles by local authority (published 23 September 2026); ONS Census 2021, TS044 and TS054 (Nomis); South Downs National Park Authority, as recorded in our RUN11 claims table; PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023), runs of 15 October 2026; NESO GB DNO licence areas (May 2024); SSEN Distribution, Who we are, and its fast-track response aim as recorded in our RUN10 claims table; Energy Networks Association EREC G98 Issue 2 (10 March 2025); Ofgem, RIIO-2 Electricity Distribution annual report 2024 to 2025, supplementary datafile.