Battery Storage Installation Guide
Home batteries store cheap or solar-generated energy for later. Installing them safely is about siting, protection and understanding the inverter arrangement.
Battery energy storage systems (BESS) let a household store solar generation or off-peak grid electricity and use it later. They are increasingly fitted alongside solar PV or on their own to exploit time-of-use tariffs.
This guide covers the practical electrical considerations — where to site a battery, how it connects through AC-coupled or hybrid inverters, the protection and notification required, and the fire-safety guidance in PAS 63100.
Key takeaways
- Batteries connect either AC-coupled (own inverter) or DC-coupled through a hybrid inverter shared with PV.
- Siting matters for fire safety — avoid escape routes and habitable-room locations where guidance advises against it.
- PAS 63100 gives fire-safety guidance for domestic battery installations.
- The battery system needs appropriate isolation, protection and clear labelling.
- Grid-connected storage is notified to the DNO like any other connected equipment.
AC-coupled vs hybrid systems
An AC-coupled battery has its own inverter and connects to the AC side of the installation, which makes it easy to retrofit to a home that already has solar. A DC-coupled system uses a hybrid inverter shared with the PV array, which is more efficient but usually designed in from the start.
The choice shapes the wiring, the isolation points and how the battery interacts with any existing PV.
Siting and fire safety
Where the battery goes matters. Guidance steers away from siting batteries on or near escape routes, in loft spaces without protection, or against habitable rooms in ways that would spread a fire. A garage, outbuilding or suitable external wall is common.
PAS 63100 is the reference for fire safety in domestic battery installations and is worth following even where not strictly mandated.
Plan the location early
Siting drives cable runs, isolation and fire safety — agree it at survey, not when the battery arrives.
Protection, isolation and connection
Provide the isolation and overcurrent protection the manufacturer specifies, label the battery and its isolation clearly, and make sure anyone working on the installation can see there is a stored-energy source that stays live when the grid is off.
Follow the manufacturer's installation instructions closely — battery systems vary and the commissioning steps are product-specific.
Notification and certification
Grid-connected storage is notified to the DNO under the same G98/G99 framework as other connected equipment. Commission the system per the manufacturer's process, test the AC connection, and certify.
The AC circuit gets an EIC and the storage system is recorded on a commissioning certificate.
One certificate for PV and battery
TradePlanr's solar PV and battery commissioning certificate covers the storage system and any linked PV in a single signed record.
Frequently asked questions
Where can a home battery be installed?
Follow the manufacturer's instructions and PAS 63100 fire-safety guidance — typically a garage, outbuilding or suitable external location, avoiding escape routes and unprotected loft or habitable-room positions.
What is PAS 63100?
PAS 63100 is the publicly available specification covering fire safety when installing domestic electrical energy storage systems. It guides siting, protection and installation practice.
Do I need to notify the DNO for a battery?
Yes, grid-connected storage is notified under G98 or applied for under G99, the same framework as other connected generation and storage equipment.
From guidance to action
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What a consumer unit change involves — assessing the existing installation, RCBO boards and paperwork.
