Home EV charging comes in three speeds, and the right one depends on your supply, your mileage and your patience. Here’s what the numbers actually mean when the car is sitting on your driveway.
7kW AC: the overnight workhorse
The standard for UK homes on a single-phase supply. A 7kW charger adds roughly 25 to 30 miles of range per hour, which sounds modest until you remember cars sleep at home: a typical overnight window replenishes 200+ miles. For most drivers, 7kW is genuinely all the speed they need. The Tesla Wall Connector, Sigenergy’s 7kW AC unit, Hypervolt and the myenergi Zappi all live here.
22kW AC: the three-phase question
Triple the power, one big catch: 22kW AC requires a three-phase electricity supply, which most UK homes don’t have. There’s a second catch too: many EVs can only accept 7 to 11kW of AC charging regardless of the charger, because the limit is the car’s onboard converter. If you have three-phase and a car that can use it, Sigenergy’s 22kW AC charger is excellent. We’ll confirm both at proposal stage before recommending it.
25kW DC: a different animal
DC charging bypasses the car’s onboard converter entirely and feeds the battery directly, which is how motorway rapid chargers work. Sigenergy’s EV DC module builds this capability into the SigenStor tower itself, up to 25kW, drawing on solar and home battery as well as the grid. That’s several times faster than 7kW: lunch-break speed rather than overnight speed.
Who actually needs what
- Typical commuter, charges overnight: 7kW AC. Spend the difference on more battery or panels.
- High-mileage driver, unpredictable days: the DC module earns its keep every week.
- Two EVs on one driveway: DC lets one car gulp while the other sips overnight.
- Three-phase home, capable car: 22kW AC is a strong middle path.
Whichever speed fits, the charger should be designed into your solar and battery system, not bolted on after. Solar-priority charging, tariff scheduling and one app only come from one design. That’s the thinking behind our EV charging page.
This guide is general information, not advice for your specific property. Every Powergy proposal is modelled on your actual roof, usage and tariff. Figures reflect typical UK conditions at the time of writing.