A standard EV charger has no awareness of your home battery - it draws power from whatever source is available, which can quietly deplete a battery you installed to manage household energy and leave it unavailable when you actually need it. If you already have a home battery and are adding a charger, or the other way round, that coordination problem is worth solving before installation rather than after; the starting point is an assessment of your battery platform and supply capacity. A battery-linked EV charger communicates with your energy management system to prevent this. Priority rules can be set to protect battery reserve, draw from solar surplus when available, and schedule grid charging during off-peak periods. The result is an EV charging system that works alongside your battery rather than competing with it. We install and commission battery-linked EV chargers across Surrey and South West London, integrating with Tesla Powerwall, SolarEdge, GivEnergy and other platforms. See also our battery storage and battery and EV charger pages.
Integrating an EV charger with an existing battery storage system requires firmware-level co-commissioning - not just a standard charger installation. We have specific experience with Tesla Wall Connector and Powerwall Gateway configuration, SolarEdge EV integration, and GivEnergy EMS priority rule programming. We confirm the correct integration approach for your specific platform at survey stage.
Where the hardware allows it, we configure battery-linked installations so that solar generation, battery state-of-charge and EV charging schedule are all visible from a single manufacturer application. We commission the battery and EV charger as a co-designed system rather than two separate installations that have to be reconciled later.
Some residential solar, battery storage and qualifying energy-saving installations may be eligible for 0% VAT, subject to current HMRC rules and confirmation at quotation. This can apply to the home battery storage component of a combined battery and EV charger project - the battery hardware, cabling and installation labour - while the EV charger circuit is rated at standard VAT. We identify and apply the correct split at quote stage.
We review your existing battery platform, gateway firmware, solar inverter and incomer capacity to confirm the charger hardware and EMS integration pathway before any equipment is ordered.
Battery reserve thresholds, EV priority hierarchy, DLB parameters and RCBO specification documented and confirmed before installation day.
Charger installed with concealed cable routing, linked to battery gateway, and priority rules verified under live load conditions before sign-off.
Full test schedule completed, single manufacturer app configured with all system components visible, and DNO notification submitted by our team.
Every home battery system is installed with a precise financial strategy: charge overnight from ultra-cheap grid power, discharge during peak hours to avoid expensive imports, and reserve a minimum threshold for emergency backup.
A standard EV charger connected to the same supply knows nothing of this strategy. When you plug in your Porsche Taycan, it draws at 7kW from whatever source has lowest impedance - which on many properties means the home battery. A 13.5kWh Tesla Powerwall depleted by EV charging at 7kW is empty in under two hours. The 4 to 8 GBP arbitrage saving that battery was positioned to execute that evening is forfeit. A battery-linked charger solves this by communicating with the battery energy management system, holding EV charging if the state-of-charge approaches the defined minimum threshold, and only drawing from the grid during confirmed off-peak windows when electricity costs less than the stored battery energy it would otherwise consume.
The most elegant battery-linked EV integration available to a luxury homeowner is the native Tesla ecosystem: a Tesla Wall Connector communicating directly with the Powerwall 3 Gateway, controlled from a single app.
When co-commissioned as a unified system, the energy routing is managed by the Powerwall Gateway rather than two separate systems attempting to co-ordinate. The Gateway receives generation data from the solar inverter, monitors the battery state-of-charge, and instructs the Wall Connector to charge from surplus solar when available, draw from battery power only within policy limits, or wait for the Octopus Intelligent off-peak window when grid rates fall to 7p per kWh. From the homeowner perspective, a single Tesla app shows solar generation, battery percentage and current charge rate on one screen - no platform switching, no operational complexity, no guesswork.
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Not every battery-equipped estate runs the Tesla ecosystem. For properties with SolarEdge inverters, GivEnergy or SMA Sunny Boy Storage platforms, we specify and commission the correct battery-linked charger for the installed energy management system.
The SolarEdge EV charger integrates natively with the SolarEdge Home Hub inverter and Home Battery, giving the same unified app experience within the SolarEdge monitoring platform. For GivEnergy installations, the GivEnergy EMS allows priority rule configuration that holds or throttles EV charging whenever the battery state-of-charge approaches its reserve threshold. For properties with an existing EMS that lacks native EV charger integration, we specify compatible third-party chargers - including the Ohme Pro, which reads household load and battery status via API and adjusts its charging schedule accordingly. In every case, integration is verified under live conditions: priority rules tested, reserve thresholds confirmed, and app state verified before sign-off.
Installing a battery-linked EV charger alongside an existing or new battery system unlocks three compounding advantages: potential VAT savings, rigorous infrastructure protection, and the same concealed aesthetic standard we apply to every premium installation.
The home battery storage component of a combined battery and EV charger project may qualify for 0% VAT under current HMRC legislation, subject to confirmation at quotation - applied to the battery hardware, cabling and installation labour at invoice where eligible. For example, on a Tesla Powerwall 3 installation priced in the region of 9,500 to 12,000 GBP, this could save approximately 1,900 to 2,400 GBP at the point of commissioning where eligible, with the exact figure confirmed at quotation stage. Dynamic Load Balancing ensures the main fuse is protected against the combined demand of a simultaneously charging battery and EV charger - a CT clamp at the incomer monitors total live demand and throttles EV charge current if the combined load approaches the fuse limit. All cable routing is planned for full concealment before any work begins, preserving the architectural finish of your Surrey estate or SW London property.
"The Tesla Wall Connector and Powerwall are linked as one system - exactly as they should be. The app shows everything on one screen and the car charges overnight without touching the battery reserve. It simply works the way you expect expensive technology to work."
"We already had a battery and the charger another company quoted would have had no communication with it at all. These engineers explained the conflict problem immediately, specified the right hardware, and co-commissioned everything properly. Our arbitrage savings are running exactly as modelled."
"The potential VAT saving on the battery component was a genuine surprise - nobody else had mentioned it. On a Powerwall 3 that is a significant reduction at invoice where eligible. The DLB commissioning meant we had no concerns about simultaneous charging and I have not had a single fuse trip."
"The GivEnergy EMS was configured with a minimum reserve threshold before the charger was even ordered. They tested the priority rules were firing correctly under live load before signing off. That level of commissioning discipline is exactly what you are paying for."
When battery-linked, the EV charge rate is managed dynamically: drawing at full 7kW from solar surplus or cheap off-peak grid, throttling to 0 if the battery approaches its reserve threshold, and resuming automatically when headroom returns. The charge rate is a managed variable, not a fixed setting. We configure the throttling parameters as part of the EMS co-commissioning.
The answer depends on your battery platform. Powerwall 2 and 3 owners achieve the tightest integration with the Tesla Wall Connector via Gateway co-commissioning. SolarEdge Home Battery owners have a native path via the SolarEdge EV charger. For GivEnergy and mixed platforms, we specify compatible chargers that read battery state via API. We confirm the hardware pathway at survey stage.
Yes, if at all possible. Co-installation reduces labour, allows a single DNO notification covering both units, and eliminates the most common integration failure: two contractors installing systems independently that then conflict at firmware level. We spec, install and commission battery and EV charger as a single co-designed programme from the outset.
Where a project is eligible under current HMRC rules, the 0% rate can apply to battery storage hardware, installation labour and associated cabling, while the EV charger hardware and its dedicated circuit remain at standard VAT. We identify the qualifying battery component at quote stage and apply the split correctly at invoice.
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A 100A single-phase supply running a battery charge cycle at 3.6kW and an EV charger at 7kW is drawing 10.6kW before any other estate demand. On a property also running a heat pump and kitchen, this risks a trip. We calculate the combined maximum demand at survey stage and specify DLB or a supply upgrade where required.
A battery-linked system designed for one EV can be sized to accommodate a second charger or a future bidirectional charger if cable sizing, gateway capacity and DLB headroom are planned from the outset. We consider the realistic load you may carry in the future - not just the vehicle currently in the garage. See our EV charging hub for an overview of all EV services.
Yes. A standard 7kW EV charger draws from whatever source has lowest impedance at the incomer - which commonly includes the home battery if it is in discharge mode. A 13.5kWh Powerwall can be fully depleted in under two hours at that rate, eliminating the battery's ability to execute its peak-avoidance strategy. A battery-linked charger communicates with the energy management system and holds EV charging whenever the battery state-of-charge approaches its defined minimum reserve threshold.
The Tesla Wall Connector is the native ecosystem solution. When co-commissioned with the Powerwall 3 Gateway, the Wall Connector is controlled directly by the Gateway energy management system - routing surplus solar to the vehicle first, protecting the battery reserve, and scheduling off-peak grid charging automatically. The entire system is visible from one Tesla app. We commission the complete Powerwall and Wall Connector programme as a unified system, verified under live conditions before handover.
Some residential solar, battery storage and qualifying energy-saving installations may be eligible for 0% VAT, subject to current HMRC rules and confirmation at quotation. This can apply to the home battery storage component - the battery hardware, BMS, installation labour and associated cabling - while the EV charger hardware and its dedicated circuit are rated at standard VAT. The saving depends on the battery hardware being installed; we identify and apply the correct split at quote stage. See our battery storage page for more on battery systems.
When both the battery charge cycle and EV charger are drawing power simultaneously, combined load can approach or exceed the main fuse rating on a single-phase 100A supply. Dynamic load balancing installs a CT clamp at the incomer to monitor total live demand and throttle EV charging current automatically whenever the combined load approaches the fuse limit. Both the battery charge cycle and EV session continue simultaneously - safely, automatically, and without homeowner intervention. If your consumer unit or incomer supply is close to capacity, see our fuse board replacement page for guidance on upgrading supply headroom.
Yes. In a solar, battery and EV setup, the energy management system can be configured to prioritise solar generation, then battery discharge, then grid. During the day, surplus solar not used by the household can charge the battery; once the battery reserve threshold is met, surplus can also flow to the EV charger directly. At night, the EV draws from the battery first. The combination can improve energy self-sufficiency for vehicle charging, depending on your system size and usage pattern. See our solar-compatible EV chargers page and our EV charging hub for an overview.
A battery and EV charger installed by two separate contractors without system-level co-commissioning will conflict with each other from day one. The EV charger treats the battery as just another grid source. The battery is depleted before it can execute its arbitrage strategy. Neither system performs as specified.
What our co-commissioned integration includes:
"Two systems installed separately is not one integrated system. It is two conflicts waiting to happen."