Battery Payback Calculator
A home battery is not just for solar owners. With time-of-use tariffs offering 7p/kWh overnight electricity and peak rates at 26.11p/kWh, you can save real money by charging a battery when electricity is cheap and running your home off it when prices are high. This calculator shows your payback period, annual saving, and return on investment - so you know whether a battery makes financial sense for your household.
Your Battery Setup
Enter your battery cost, electricity rates and how much of your daily usage you can shift to off-peak hours. We work out the payback.
How load shifting saves you money
Your battery acts as a time machine for electricity. Charge it at 7.5p/kWh overnight, then use that stored energy to run your washing machine, dishwasher, immersion heater and evening lights during the day when grid electricity costs 26.11p/kWh. Every kWh you shift saves you the difference - about 19p in this example. A 5kWh battery shifted daily saves roughly £310/year. Over a 10-year battery lifespan that is over £3,000, well above the battery cost.
This is self-consumption shifting, not export arbitrage. The real value of a home battery is avoiding buying expensive peak-rate electricity, not selling it back to the grid. SEG export rates (12-16p/kWh) are consistently lower than peak import rates (24-35p/kWh), so every unit you store and use yourself saves more than a unit you export.
Current UK Time-of-Use Tariffs
These are real tariffs available to UK homes with smart meters as of August 2026. Pick the one that matches your usage pattern and plug the numbers into the calculator above.
| Tariff | Off-peak rate | Peak rate | Off-peak window | Best for |
|---|---|---|---|---|
| Octopus Go | 7.5p | 26.11p | 00:30-04:30 (4 hrs) | 5-10kWh battery, EV owners |
| Octopus Intelligent Go | 7p | 26.11p | 23:30-05:30 (6 hrs) | Larger batteries, Octopus-compatible EV |
| E.ON Next Drive | 6.7p | 25.4p | 00:00-07:00 (7 hrs) | Biggest off-peak window, any EV |
| British Gas Electric Driver | 7.9p | 25.1p | 00:00-05:00 (5 hrs) | EV owners with British Gas |
| OVO Charge Anytime | 7p | 24.7p | Any time (smart charging) | EV owners - flexible timing |
Rates are for regions with average standing charges as of August 2026. Exact rates vary by region and are subject to the Ofgem price cap. Check your supplier's website for your postcode's specific rates. These are EV tariffs - you do not always need an EV to sign up for Octopus Go, but some suppliers require one for the cheapest rates.
Common Questions
How does a home battery save money on electricity?
A home battery saves money by time-shifting your electricity consumption. You charge it during cheap off-peak hours (e.g. 7.5p/kWh overnight on Octopus Go) and then use that stored energy during expensive peak hours (e.g. 26.11p/kWh during the day). The difference - about 19p per kWh in that example - is your saving on every unit you shift. With a typical 4-5kWh daily shiftable load, that is roughly £250-320 per year. Over a 10-year battery lifespan, the saving comfortably exceeds the battery cost, and that is before adding solar panels to the mix.
What is the best time-of-use tariff for battery storage in the UK?
As of August 2026, the best TOU tariffs for battery owners are Octopus Go (7.5p/kWh off-peak, 4 hours overnight), Octopus Intelligent Go (7p/kWh, 6 hours), and E.ON Next Drive (6.7p/kWh, 7 hours midnight-7am). For homes with larger batteries, Octopus Flux is also worth considering - it pays a higher export rate during peak hours (4pm-7pm) if you choose to discharge your battery to the grid, but the real savings come from avoiding peak import, not from exporting.
How long does a home battery take to pay for itself?
A typical 5.2kWh home battery costing £2,000-2,700 installed, paired with a time-of-use tariff, pays for itself in 7-10 years through load shifting alone. If you also have solar panels, the payback drops to 5-8 years because the battery stores free solar energy for evening use. Most LiFePO4 batteries are warrantied for 10 years and 6000+ cycles, so the battery should comfortably outlast its payback period. After payback, all savings are pure profit.
Do I need solar panels for a home battery to make financial sense?
No. A home battery can pay for itself without solar panels, purely by charging on cheap off-peak electricity and discharging during expensive peak hours. This is called time-of-use arbitrage or load shifting. With a 15-18p/kWh spread between off-peak and peak rates, a 5kWh battery used daily can save £250-330 per year. Adding solar improves the payback further because you store free solar electricity rather than buying even off-peak power, but solar is not required for a battery to be worthwhile. Plenty of UK homes with time-of-use tariffs and no solar are already doing this.
Which battery brands offer the best payback in the UK?
For the best payback, look at cost per usable kWh. GivEnergy (5.2kWh at £2,000-2,500 installed) and Fogstar (5.1kWh at £1,500-2,000) offer the lowest upfront cost per kWh and are popular with UK installers. Pylontech US5000 (4.8kWh at £1,300-1,600) is the go-to for DIY builds and pairs well with most hybrid inverters. All three are LiFePO4 chemistry with 10-year warranties and 6000+ cycle ratings. Pre-built AC-coupled batteries like the Tesla Powerwall 3 cost significantly more (£5,000-8,000) and take roughly twice as long to pay back, though they offer higher peak power output for whole-home backup.