How Home Battery Storage Works
Quick answer
A home battery charges from the grid overnight on a time-of-use tariff, when electricity costs less, and powers your home during the day when the rate is higher. Solar panels are optional: if you have them, the battery also stores surplus daytime generation. It connects to your consumer unit and is monitored through an app on your phone.
Key facts
- A battery charges overnight when electricity is cheaper and runs the house by day
- Solar panels are optional — the core saving works without them
- A smart meter and time-of-use tariff are required
- The battery connects to your consumer unit like any other circuit
- Most batteries are warrantied for around 10 years or 6,000 cycles
- Interest-free credit up to £30,000, subject to status
Last updated: 28 October 2026
Last updated: 28 October 2026
What does a home battery actually do?
A home battery stores electricity when it is cheap and releases it when it is expensive. It charges overnight on a low time-of-use tariff and powers your house during the day, so you pay the overnight rate instead of the peak rate.
Think of it as a buffer between the grid and your home. The grid sells electricity at different prices depending on the time of day. The battery buys when the price is low (overnight) and sells to you when the price is high (daytime). You never see the difference — your lights and appliances work exactly the same.
The battery connects to your consumer unit, just like any other circuit. A monitoring app shows you how much it charges and discharges each day, so you can see the saving in real time.
Do I need solar panels for a battery to work?
No. A battery works on its own, charging from the grid overnight. Solar panels are optional and can be added later. The battery does not depend on solar generation to save you money.
The benefit comes from the gap between your day rate and your overnight rate, not from generating your own electricity. The battery stores power bought at the lower overnight rate, and the house uses that stored power instead of buying at the higher daytime rate.
Solar panels add a second charging source: they charge the battery from your own roof during the day. But the core saving — buying cheap overnight and using it during the day — works without any solar at all.
What is a time-of-use tariff?
A time-of-use tariff charges different rates at different times of day. The overnight rate is much cheaper than the daytime rate. A battery needs a time-of-use tariff to buy electricity cheaply and store it.
Most energy suppliers offer time-of-use tariffs, but the cheapest overnight rates are generally open to households that already have storage or generation installed. A smart meter is required so the supplier can track when you use electricity.
The surveyor helps you identify suitable tariffs for your area. You do not need to switch supplier before installing a battery, but you will need a time-of-use tariff to get the benefit.
How is the battery installed?
The battery is mounted on a wall or floor, connected to your consumer unit, and commissioned in one to two days. A surveyor visits first to check your electrical setup and specify the right capacity.
The surveyor checks your meter position, fuse board, available space, and household usage. You receive a written quotation with the battery capacity, inverter, installation cost, and warranty terms. Nothing is booked until you sign.
We install through MCS-certified partners. The battery, inverter, and monitoring system are commissioned and tested on site. You get an app to monitor charging and discharging in real time.
How long does a home battery last?
Most home batteries are warrantied for around 10 years or 6,000 charge cycles. MCS-listed equipment and warranty terms are confirmed in writing on your quotation.
A charge cycle is one full charge and discharge. In practice, a battery does one cycle per day — charging overnight and discharging during the day. At one cycle per day, 6,000 cycles is roughly 16 years, though the warranty terms specify the covered period.
The battery degrades gradually over time, like any battery. The warranty specifies the minimum capacity at the end of the warranty period, so you know what performance is guaranteed.
What happens on a day with no sun?
The battery charges from the grid overnight regardless of weather. Solar is a bonus, not a requirement. On a cloudy winter day, the battery still charges overnight and saves you money the next day.
This is the key difference between a battery and a solar-only system. Solar panels produce nothing at night and very little in winter. A battery, charged from the grid, works every day of the year.
In summer, if you have solar panels, the battery may charge from solar during the day and from the grid overnight. In winter, it charges almost entirely from the grid. Either way, the saving comes from the tariff gap.
Frequently asked questions
Do you install home batteries in Dundee?
Yes. We install home battery storage across Dundee and the wider Tayside area through our MCS-certified partners. Every installation starts with a survey at your home, where the meter, consumer unit and available space are checked, followed by a written, no-obligation quote that sets out the battery, the work involved and the warranty terms.
Can I add a battery to my existing solar panels?
Yes. Most existing solar PV systems can take a battery. With a hybrid inverter the battery connects directly; with a standard string inverter, an AC-coupled battery with its own inverter is added. Your panels keep generating as before, and the surveyor confirms which setup suits your system and what the network operator needs to be told.
Is finance available?
Interest-free credit up to £30,000, subject to status. The terms are shown on your written quotation alongside the full installation price. You are never obliged to use credit: you can pay in full or arrange your own finance, and the installation price stays the same whichever you choose.
How do I get a quote?
Call 0141 230 0198 or send the quote form on this page. We call you back within one working day to book a survey at your home. After the survey you receive a written, no-obligation quote with the battery size, every cost line and the warranty terms, so you can decide in your own time.
Do I need a smart meter?
Yes. A smart meter is required for a time-of-use tariff, which is what makes the battery worth having. If you do not have one yet, your energy supplier can arrange the installation. The surveyor checks whether your current meter can support a time-of-use tariff before the quote is written.
Can I run my whole house on a battery?
A battery can power most household loads during the day. The capacity you need depends on your usage. The surveyor sizes the battery to your actual consumption so it covers your typical daytime demand. Very high loads, such as electric showers, may still draw from the grid.
Does the battery work in a power cut?
Some batteries offer backup power functionality, but this depends on the model and installation. The surveyor can advise whether backup power is available for your setup. Backup usually needs extra equipment and covers selected circuits, so it is listed separately on the quotation if you want it.
How much does installation cost?
Installation is priced after a survey, because the battery size, your consumer unit and the position of the meter all affect the work involved. The written quotation itemises every cost, with no obligation to go ahead. Interest-free credit up to £30,000, subject to status.
Can I add solar panels later?
Yes. The battery is designed to accept solar input. Many households start with a battery alone and add solar panels later. The battery works with or without solar. The surveyor notes any roof or inverter details now that would make adding panels later easier.
Reviewed by the Scottish Energy Efficiency team. Last updated: 28 October 2026.
Ready to get your written quotation?
Survey first, written quotation second. No deposit, no obligation. We call you back within one working day.
- Home survey before any price
- We install through MCS-certified partners
- Interest-free credit up to £30,000, subject to status.