EV charging speed explained: why the biggest number is not always best
Updated: Oct 16
A charger labelled 150 kW sounds dramatically better than one labelled 7 kW. For a long motorway journey, it may well be. For a car parked at home all night, that comparison misses the point.
Power and time are different things
Charging power is measured in kilowatts (kW); the energy added to the battery is measured in kilowatt-hours (kWh). As a rough illustration, a 7 kW charger running for six hours could deliver about 42 kWh before charging losses and other limits. Actual charging varies, and the car may not draw the charger's full rated power.
Why public rapid charging slows down
The number printed on a rapid charger is its maximum capability, not a promise of constant power. The car has its own charging limit, and charging commonly slows as the battery fills. Battery temperature, starting charge level and whether power is shared can all affect a stop.
The useful question is: how much time do you have?
At home, many cars sit parked for ten or more hours. At a motorway service station, drivers want to leave in minutes. Those are different problems, and they call for different equipment. For most homes, reliable scheduling, suitable installation and easy everyday use matter more than headline speed.
Think beyond the charger
Before paying extra for a higher-powered unit, check what the vehicle can accept on AC charging and what the property's electrical supply can safely support. A qualified installer can explain any constraints. Avoid treating an advertised maximum as a guaranteed charging rate.
Logic Charge helps you compare the practical options without promising a particular speed or installation price. If you want to discuss your vehicle and parking arrangement, send an enquiry through our website.
Further reading: International Energy Agency, Global EV Outlook 2026, Electric vehicle charging — https://www.iea.org/reports/global-ev-outlook-2026/electric-vehicle-charging-chap-6-and-10
Research checked 16 October 2026. This is documentary research; it does not replace an assessment of your vehicle, property or electrical installation.
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