Charging two EVs on one home supply
Two cars, one supply. Load balancing is the feature that makes it possible without an expensive upgrade.
Two electric cars in one household is increasingly normal, and it is usually far less of a problem than people expect.
Start with the arithmetic
A single-phase supply comfortably runs one 7.4 kW charger. Two at full rate is 14.8 kW, which on top of household demand will exceed many domestic supplies.
But that assumes both cars need a full charge simultaneously, which is rarely true.
Option 1: one charger, taken in turns
The simplest answer, and adequate for most households.
Overnight at 7.4 kW adds roughly 220 miles. Two cars each doing average mileage need far less than that combined, so alternating nights usually covers both.
Choose untethered so one cable serves whichever car is on the drive — the reasoning is in tethered vs untethered.
Option 2: two chargers with load balancing
Load balancing lets two units share the available capacity dynamically. If one car finishes, the other ramps up.
Both cars are plugged in every night, and neither trips the supply. This is the right answer if:
- Both cars do substantial daily mileage
- Charging windows overlap and cannot be staggered
- You want to stop thinking about it
Confirm the chargers support balancing with each other — it is not a universal standard, and mixing brands rarely works.
Option 3: supply upgrade
Possible, expensive, and usually unnecessary. Explore load balancing first.
Practical points
One tariff window, two cars. If your cheap window is four hours, two cars sharing it get roughly half each. Load balancing handles the sharing; you may need to accept that neither reaches full every night. In practice that is fine.
Different connectors? Untethered solves it. Two cables, one socket.
Different charging speeds? The slower car will finish later. Balancing gives the freed capacity to the other one.
What to tell the installer
Say up front that there are two EVs. It changes the recommendation, the load calculation and possibly the consumer unit work — and it is much cheaper to plan for than to retrofit. See what installation costs.
In pictures
Common questions
Can I just fit two chargers?
Only if the supply can carry both at full rate, which most domestic supplies cannot. Load-balancing chargers share the available capacity instead of tripping the main fuse.
About the author
ElectraMile EditorialEditorial desk
The ElectraMile editorial team covers charging, running costs and EV ownership for readers in the UK and US.
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