EV charging speeds explained: 7kW, 50kW and 150kW
Published on 2026-08-10
The number on the charger is a ceiling, not a promise. What you actually get depends on your car, your battery's state of charge and its temperature — and on a time-billed charger, that difference is money.
The tiers, and what they are for
Slow AC, around 3kW, is a domestic three-pin socket or an older unit. It adds range at roughly walking pace over a day and is a last resort rather than a plan.
Fast AC, typically 7kW at home and 7 to 22kW in public bays, is the workhorse. Overnight at 7kW is enough to refill most of a battery, which is why home charging works so well: the car is parked for far longer than it needs.
Rapid DC starts around 50kW, and ultra-rapid runs from roughly 100kW to 350kW. These exist for one job — getting you back on the road during a long journey — and they are priced accordingly.
Why you rarely see the number on the sign
On AC, the limit is usually your car, not the charger. Every EV has an onboard charger with a maximum AC rate, commonly 7kW or 11kW. Plug a 7kW car into a 22kW post and you get 7kW — the extra capacity does nothing for you.
On DC, the limit is the battery's willingness to accept charge, and that changes constantly during the session. The rate is highest when the battery is fairly empty and tapers sharply as it fills, which is why charging from 10% to 60% is far quicker than 60% to 100% even though it is more energy.
Temperature matters too. A cold battery accepts charge slowly until it warms up, so a rapid stop early on a winter journey can deliver well below the headline figure. Some cars precondition the battery when you navigate to a charger, which is worth enabling if yours can.
Where speed turns into cost
If the charger bills per kWh, speed changes how long you wait but not what you pay. If it bills per minute, speed is the price: a car limited to 50kW on a 150kW unit pays roughly three times as much per kWh as a car that can use the full rate.
That is the strongest argument for knowing your car's real DC curve rather than its headline peak. A car advertised at 150kW that holds that rate only briefly, then settles at 70, behaves like a 70kW car for pricing purposes.
It also argues for stopping earlier and more briefly on a long trip. Two stops in the fast part of the curve usually beat one long stop that runs into the taper, both for time and, on time-billed networks, for money.
FAQ
Why is my car charging slower than the charger's rating?
Usually because your car is the limit, not the charger. On AC, your onboard charger caps the rate — often at 7kW or 11kW. On DC, the battery accepts less as it fills and when it is cold, so the peak figure applies only briefly.
What is the difference between AC and DC charging?
AC charging goes through your car's onboard charger, which caps it at 7 to 22kW for most cars. DC charging bypasses that and feeds the battery directly, which is how rapid units reach 50kW and above.
Is it better to do one long charging stop or two short ones?
Usually two short ones. Charging is fastest in the lower part of the battery and tapers above roughly 80%, so two stops from a low state of charge often take less total time than one that runs into the taper.
Does charging speed change what I pay?
On a per-kWh charger, no — only how long you wait. On a per-minute charger it changes everything, because a slower car buys less energy for the same billed time.
Always find the cheapest option
Refil shows the cheapest EV charger near you on the map, plus fuel prices in Spain, France, Germany, Italy and Portugal. Download it free on the App Store.
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