Home Battery Installation
— Add a Battery to Existing Solar
Retrofit battery storage to solar panels you already have, or add a standalone battery with no solar at all. MCS & NAPIT certified. Free no-obligation survey.
Two Ways to Add a Battery
You Already Have Solar — No Battery
Most solar systems installed without a battery use around 40% of what they generate on-site — the rest is exported at a lower rate than you buy it back at. We assess your existing inverter and advise whether a hybrid inverter upgrade is needed, or whether an AC-coupled battery can be added without touching your panels or existing inverter at all.
You Want a Battery — No Solar at All
A standalone battery doesn't need solar panels. It charges from the grid overnight on a cheap-rate tariff (e.g. Octopus Go at ~7.5p/kWh) and discharges during expensive peak periods — plus backup power on systems with that functionality. Straightforward single-visit install.
Battery Retrofit Costs in Milton Keynes
Indicative prices for standalone battery installation, supply and commissioning included. Retrofit jobs needing inverter compatibility work are always confirmed and priced at your free survey — never as a day-rate.
| System | Capacity | Installed Cost | Additional Annual Saving |
|---|---|---|---|
| Fox ESS EP6 | 5.76 kWh | From £4,400 | ~£110/yr |
| Fox ESS EP12 | 11.52 kWh | From £5,300 | ~£220/yr |
| SigenStor BAT 6.0 | 5.84 kWh | From £5,400 | ~£130/yr |
| SigenStor BAT 10.0 | 8.76 kWh | From £5,900 | ~£175/yr |
Prices include supply, installation and commissioning. Estimated extra saving from storing your own solar, for a south-facing 4kWp system generating 3,600 kWh/year: the battery raises the share used at home from 40% to 62–82% depending on size, with each stored unit worth 26.32p/kWh instead of a 12p/kWh export payment. Charging on a cheap overnight tariff can add more. Your free survey confirms exact figures — including any inverter compatibility work.
Brands You Actually Fit
We install a range of battery systems and recommend the one that suits your existing setup and budget — not the one with the biggest margin.
Sigenergy (SigenStor)
Hybrid inverter and battery system. See the SigenStor range →
Fox ESS
Hybrid inverter batteries from 5.76kWh, expandable as your needs grow.
ECOFlow
Flexible AC-coupled options, well suited to retrofit without touching your existing inverter.
Tesla Powerwall
13.5kWh storage, 10-year warranty. See Powerwall installation →
How Battery Retrofit Works
Assessment & Compatibility Check
We assess your existing solar system (or your electrics, if you have no solar), your daily usage patterns, and your grid tariff. We confirm whether your current inverter supports a hybrid upgrade or whether an AC-coupled battery is the better fit — and give you a fixed price in writing.
Installation
Retrofit installation is typically completed in a single day. We mount the unit (usually in a garage or utility room), connect it to your existing solar system or consumer unit, and commission it fully. The site is left clean and tidy.
Handover & Monitoring
We show you how to use the monitoring app so you can see your generation, storage, and usage in real time, configure any smart tariff integrations, and hand over all documentation.
Get Your Free Battery Quote
Tell us whether you already have solar and we'll call you to arrange a free, no-obligation survey — usually within one working day.
- Retrofit or standalone — either way, one fixed price
- MCS & NAPIT certified engineers, based in Bletchley
- Deposit protected as an IWA Approved Installer
Battery Retrofit FAQs
Yes — we can retrofit battery storage to most existing solar installations. We'll assess your current inverter and advise whether a hybrid inverter upgrade is needed or whether an AC-coupled battery system would work better. Both options are available.
A home battery system in Milton Keynes typically costs from £4,400 installed depending on capacity (5.8–17kWh). Most systems land between £4,400 and £7,200 installed, depending on capacity and brand. Price your own battery on our calculator.
Yes — a standalone battery can charge from the grid overnight on a cheap-rate tariff and discharge during expensive peak periods, with no solar required. It also provides backup power on systems with that functionality.
A home battery raises how much of your solar you use yourself, from around 40% without storage to 60–80%. For a typical 4kWp system generating 3,600 kWh/year, we estimate that adds around £110–£220 a year on top of what solar already saves, because electricity you store and use is worth 26.32p/kWh rather than the 12p/kWh you would be paid to export it. If you also charge the battery on a cheap overnight tariff, the saving can be higher; we work that out for your tariff at the survey.
We install Sigenergy, Fox ESS, ECOFlow, Tesla Powerwall, and other quality battery systems. The right choice depends on your existing setup, required capacity, and budget. We'll recommend the best option during your free survey.
Get Your Free Battery Retrofit Quote in Milton Keynes
We'll assess your existing solar setup (or your electrics, if you have none), recommend the right battery, and give you a fixed-price quote in writing.
Mon–Fri, 08:00–17:00 | 1 South House, Bond Avenue, Bletchley, Milton Keynes, MK1 1SW
“Called Depth of Light because I was having trouble with my electricity tripping when solar panels kicked in each morning. Matt came round within a few days and spoke with Solis. Between them the fault was identified and Matt came and fitted a new RCD. Fast, professional, friendly service. Would recommend.”
“Matt did an amazing job replacing our old fuse box! He was super clean, kept us informed every step of the way, and did a really professional job. We’ve used him for various other work since and we’ll definitely keep using his services again.”
