EVs: The New Home Batteries

The New MX7 device allows electric cars to supply power back to homes and the grid

14 Jul 2025

Electric cars are quietly changing their role. From next summer, British households will be able to install the MX7, a home charger from Humax, that allows cars to feed energy back into the grid. The device, launched at the Everything Electric Show, marks a small step towards turning cars into part of the energy infrastructure.

The MX7 is a 7kW charger that comes in socket and tethered formats. It supports Power Line Communication and complies with ISO 15118, a standard for bidirectional power transfer. This lets energy flow not only from the grid to the car but back again to homes or the wider network.

Its main appeal lies in clever automation. The charger draws power during cheaper off-peak periods, captures surplus energy from rooftop solar panels and releases electricity during peak demand. Installation avoids costly rewiring, making it easier to fit into existing homes.

Such features hint at a broader shift. Electric vehicles could evolve from simple transport into mobile batteries, helping to balance supply and demand. By smoothing out fluctuations in renewable energy, they could lessen strain on the grid and reduce household bills.

Yet, much depends on policy. “Revenue potential and energy export depend on evolving UK regulations and permissions for bidirectional setups,” admits Humax. Early trials with energy providers will test the commercial case and highlight the bureaucratic hurdles.

Still, the technology’s direction is clear. As carmakers, utilities and tech firms move towards shared standards, chargers like the MX7 show how electric cars might soon power more than just journeys. They could keep the lights on, too.