EV Charging Guide
EV Charging Speeds Explained
Slow, fast, rapid and ultra-rapid — what each category means in kW, how long they take, and why speed usually comes with a higher price tag.
UK charge point listings throw around terms like "fast", "rapid" and "ultra-rapid" as if they're precisely defined — they're not official units, just industry shorthand for power bands. Knowing which band a charger falls into tells you roughly how long you'll be stood there, and roughly what it'll cost.
Work out your own charging time
Enter your battery size and a charger's kW rating to see exactly how long a top-up will take.
The four speed bands
| Category | Typical power | Current type | Where you'll find it |
|---|---|---|---|
| Slow | 3–6kW | AC | Home "granny" cable, some lamppost chargers |
| Fast | 7–22kW | AC | Home wallbox, workplace, destination car parks |
| Rapid | 50–99kW | DC | Motorway services, retail rapid hubs |
| Ultra-rapid | 100–350kW | DC | Newer motorway/hub sites, high-power charging bays |
Your car's onboard charger and battery both cap the power it can actually accept, so plugging into a 350kW ultra-rapid unit doesn't guarantee 350kW — most current EVs top out well below that, and DC charging also tapers as the battery fills, especially above about 80%.
Why speed and cost usually move together
In the UK, the fastest chargers tend to be the most expensive per kWh. Zapmap's weighted averages put public slow/fast charging around 54p/kWh and rapid/ultra-rapid around 79p/kWh — a premium you're paying for convenience and speed on a journey, not for the electricity itself, which costs the operator roughly the same regardless of the plug.
See the full UK charging cost guide for exact rate comparisons, or the charging time calculator to plug in your own numbers.
Which speed do you actually need?
- Overnight at home: a 7kW fast charger comfortably fills most batteries in one sitting — no need for anything quicker.
- Topping up while shopping or at work: fast (7-22kW) destination chargers suit a few hours of parking.
- Motorway journeys: rapid or ultra-rapid is the only practical option for a 20-30 minute stop.
Frequently asked questions
What's the difference between fast and rapid EV charging?
Fast charging is AC power, typically 7-22kW, common at home and destination chargers. Rapid charging is DC power, typically 50kW and above, used for quick top-ups on longer journeys.
How fast is ultra-rapid EV charging?
Ultra-rapid chargers typically deliver 100-350kW DC, capable of adding significant range in 15-20 minutes on a compatible car, though most vehicles can't accept the full 350kW.
Does charging speed affect cost per kWh?
Yes. Faster charging is generally more expensive per kWh in the UK — rapid/ultra-rapid averages around 79p/kWh versus around 54p/kWh for slower public AC charging, and far less at home.