Cheapest electricity tariff for a home battery in the UK (2026 guide)

If you charge mostly overnight

Look for a tariff with a low night rate and a stable peak rate. Make sure the off‑peak hours match when your battery can actually charge.

If you have solar + battery

Consider tariffs that combine good off‑peak import with a competitive export rate. Export rules and eligibility vary, so check before switching.

If your usage is fairly even all day

A time‑of‑use tariff can still be good, but only if you can shift enough demand. Otherwise a strong single‑rate tariff may be cheaper overall.

1) Confirm your meter & eligibility

• Smart meter: many time‑of‑use tariffs require one (and it must be communicating).
• Payment method: prices can differ for Direct Debit vs prepayment meters.
• Region: standing charges and unit rates vary across Great Britain.

2) Match the off‑peak window to your battery

• Check the start/end times (some are fixed; others can vary).
• Make sure your inverter can charge within the window (charging power matters).
• Plan for weekends and seasonal routines (school runs, WFH, heat pump use).

3) Check the peak rate & standing charge

• A very cheap off‑peak rate can come with a higher day rate.
• Standing charge can outweigh unit savings in low‑use homes.
• Look for exit fees and contract length if you might switch again.

Scenario A: battery only, overnight charging

A typical pattern where the battery charges off‑peak and covers evening usage.

Battery charge

8 kWh per night

Days per year

330

Off‑peak rate

12p/kWh (estimated example)

Peak rate

30p/kWh (estimated example)

Estimated off‑peak charging cost: 8 kWh × 330 × £0.12 = £316.80/year.

Assumes you can consistently shift 8 kWh into off‑peak and that your battery round‑trip efficiency and losses are not modelled here (real-world usable energy will be lower).

Scenario B: solar + battery, mixed import/export

You use solar in the day, charge from solar when possible, and top up from off‑peak in winter.

Off‑peak import

1,200 kWh/year

Day/peak import

1,000 kWh/year

Off‑peak rate

13p/kWh (estimated example)

Peak rate

29p/kWh (estimated example)

Export

1,500 kWh/year

Export rate

15p/kWh (estimated example)

Estimated import cost: (1,200 × £0.13) + (1,000 × £0.29) = £446/year.

Estimated export credit: 1,500 × £0.15 = £225/year (before any standing charge impacts).

Export eligibility can depend on metering, installation certificates, and supplier terms. Some suppliers require you to take import with them to access their export tariff.

Quick checklist: who battery tariffs suit

• You can reliably charge off‑peak (and have a compatible meter).
• Your battery has enough usable capacity to cover peak periods.
• You’re happy to schedule charging/discharging (or use automation).
• You understand the peak rate risk if you miss off‑peak windows.

Who it may not suit (or needs care)

• Homes with low usage where standing charge dominates.
• Households that can’t shift usage (e.g., day‑time electric heating without storage).
• Anyone without a smart meter where the tariff requires one.
• Renters who can’t change meter setup or have landlord constraints.

Battery settings to check before switching

• Max charge rate (kW) vs off‑peak window length.
• Minimum reserve % and discharge schedule.
• Whether the battery can be prevented from charging at peak rates.
• If you have solar: export priority vs self‑consumption.

1) Exit fees and contract terms

Fixed tariffs may charge an exit fee if you leave early. Always compare the likely benefit against the cost to move—especially if you’re mid-contract.

2) Standing charge can dominate

If you use relatively little electricity (e.g., small flat), a higher standing charge can make a tariff more expensive even with a great off‑peak rate.

3) Smart meter requirements

Many time‑of‑use tariffs require a functioning smart meter. If your smart meter isn’t communicating, billing can fall back to estimates and the tariff may not work as intended.

4) Off‑peak window too short for your battery

Example: a 10–13.5 kWh battery may not fully charge in a short window if your inverter charge rate is limited (e.g., 2–3 kW). You may end up “topping up” at the peak rate.

5) Battery efficiency and losses

Batteries aren’t 100% efficient. A typical round‑trip efficiency might be ~85–95% depending on system. That means you may need to buy more than 1 kWh to get 1 kWh usable later.

6) Export tariff eligibility and limitations

Export payments and eligibility can depend on your installation documentation, metering, and supplier rules. Some export tariffs are only available if you also take import with the same supplier.

Do I need a smart meter for a battery tariff?

Often, yes. Many time‑of‑use tariffs require a communicating smart meter so your supplier can bill different rates by time. If you don’t have one, you may be limited to standard tariffs or legacy multi-rate options.

Is Economy 7 still good for batteries?

It can be, depending on your day rate, night rate and night hours. Some Economy 7 deals are less competitive than newer time‑of‑use tariffs, but they can still work if your night rate is strong and your battery can charge fully overnight.

Can I get a cheap battery tariff if I’m on a prepayment meter?

Options can be more limited and pricing may differ from Direct Debit tariffs. If you have a smart prepayment meter, some suppliers offer competitive deals, but time‑of‑use availability varies by supplier and region.

Will I definitely save money with an off‑peak tariff and battery?

No. Savings are not guaranteed. It depends on how much electricity you can move into off‑peak hours, the size/efficiency of your battery, your standing charge, and the tariff’s peak rate. Always compare estimated annual cost, not just the cheapest unit rate.

What if my battery can’t charge fast enough in the off‑peak window?

Then a short off‑peak window may not work well. You may only partially charge and end up importing at peak rates. Check your inverter’s charge power (kW) and estimate how many kWh you can add during off‑peak hours.

Does having solar change the “cheapest” tariff choice?

Yes. With solar + battery, you should compare import and export together. A tariff with an excellent export rate may still be poor value if its import rates (or standing charge) are high for your usage pattern.

Can I switch electricity supplier if I’m renting?

In most cases, tenants can switch supplier if they pay the bill, though there can be practical constraints (e.g., landlord-managed bills, complex metering, or communal supplies). If you’re unsure, check your tenancy agreement and speak to your landlord/agent.

How long does an energy switch take in the UK?

Switching times can vary, but UK switches are typically completed within a few working days in many cases. Your supplier should confirm the expected timeline and your switch date, and you’ll have information about any cooling-off period where applicable.

Our approach

• People-first: we focus on total estimated cost and suitability for battery charging, not a single headline rate.
• UK-specific comparisons: we account for postcode/region differences and common eligibility rules (smart meters, payment method).
• Practical checks: we highlight off‑peak windows, standing charges, exit fees, and export constraints where relevant.

Assumptions used in scenarios

• Example unit rates are illustrative and do not represent a specific supplier offer.
• We assume consistent off‑peak charging behaviour across the year in Scenario A.
• We do not model battery degradation, warranty terms, dynamic pricing volatility, or all losses (efficiency varies by system).

Limitations and what can change your results

Your real-world cost will depend on your half-hourly usage profile (if applicable), battery usable capacity, inverter charge/discharge limits, seasonal demand (especially electric heating/heat pumps), and whether you’re able to keep most charging inside off‑peak hours. Supplier tariffs and eligibility criteria can change quickly, and some tariffs are withdrawn without notice.