HOUSECELL
MODULAR HOME BATTERY · UK
Start with one. Stack to four. Stop guessing at the payback.
A 5kWh home battery that clips together with more of itself. Housecell shows you what it earned you today in pounds, not in kilowatt-hours, so you can tell whether it was worth it.
MCS registered · fitted in one day
PAYBACK
6y 4m
TWO UNITS · TOU TARIFF
Typical payback on a two-unit system with a time-of-use tariff: 6 years 4 months. With solar and an EV, 4 years 9 months.
CAPACITY
5.2
KWH USABLE PER UNIT
5.2kWh usable per unit, 3.6kW continuous output, four units maximum on a single-phase supply.
BLACKOUT
12ms
CUTOVER
Cuts over in 12 milliseconds. Your fridge, lights, router and one ring circuit stay live. The oven and the shower do not, and we will tell you that before you buy.
SIZING
How many units your house actually needs
Every unit is the same 5.2kWh brick. You are not buying a size, you are buying a count — and you can change the count later without changing anything else on the wall.
1
5.2 KWH
One unit
Flat or small terrace, no solar. Covers the evening peak and not much more.
2
10.4 KWH
Two units
The common answer. Three or four bed semi with around 4kW of solar.
3
15.6 KWH
Three units
Bigger house, an EV charging at home, or a heat pump running overnight.
4
20.8 KWH
Four units
The single-phase ceiling. Heat pump, EV and solar all pulling at once.
WHEN THE STREET GOES DARK
Twelve milliseconds, and a short list of things that stay on
The changeover is fast enough that your router never reboots. What it is not is a whole-house generator, and pretending otherwise is how people end up disappointed on the one night it matters.
A two-unit system runs the list below for roughly 14 hours.
STAYS LIVE
+
Fridge and freezer
+
Lights, upstairs and down
+
Router, Wi-Fi and the alarm
+
One ring circuit of your choosing
DOES NOT
—
Electric oven
—
Electric shower
—
Immersion heater
—
EV charger
TARIFF ARBITRAGE
A day of your electricity, priced
00:00
08:00
16:00
22:00
■
Charging on the cheap rate
■
Discharging through the expensive window
LAST MONTH
£71
AVERAGE TWO-UNIT SAVING
Charges on the cheap overnight rate, discharges during the expensive window, and learns your house over about three weeks. Last month the average two-unit customer saved £71.
The app reports it in pounds. Kilowatt-hours are there if you want them, on the second tab, where they belong.
INSTALLATION
One installer. One day. Nothing on the roof.
One certified installer, one day, MCS registered so you keep your export payments. No scaffolding, no roof work, no re-wiring your consumer unit.
01
Survey, then a fixed price with the tariff maths attached
02
Wall bracket, first unit, isolator — before lunch
03
Commissioning, app pairing and the MCS certificate by post
10
YEARS
Or 6,000 cycles, whichever lands later.
6,000
CYCLES
Counted by the unit, reported in the app.
80%
CAPACITY FLOOR
The number the warranty is measured against.
WARRANTY
Modules, not systems
10 years or 6,000 cycles to 80 percent capacity, whichever is later. Modules are individually replaceable so one failure does not mean a new system.
REAL NUMBERS · FOUR INSTALLED HOMES
What four actual houses banked in twelve months
A 1930s semi in Sheffield with 4kW of solar and two units: £612 saved in twelve months. The full dataset for all four homes is downloadable.
Sheffield · S7
£612
saved in twelve months
A 1930s semi with 4kW of solar and two units. Time-of-use tariff, no EV.
Bristol · BS9
£884
saved in twelve months
A 1980s detached with 6kW of solar, an EV on the drive and three units.
Leeds · LS6
£237
saved in twelve months
A Victorian terrace with no solar at all. One unit, arbitrage only.
Norwich · NR2
£498
saved in twelve months
A 2019 new-build with 3.6kW of solar, a heat pump and two units.
BOOK A SURVEY
Book a free survey and we will do the payback maths on your house
Forty minutes, no obligation, and you leave with a unit count, a fixed price and the payback in years and months for your tariff — not for a generic house that does not exist.
Surveys run Monday to Saturday · England, Wales and southern Scotland
HOUSECELL
Modular home battery · MCS registered installers · 10 year warranty