Why does charging slow down above 80%?

To protect the battery, the car reduces charging speed as it approaches full. This is called the charging curve. Most rapid chargers are most effective from 10-80%, which is why 80% is the commonly quoted rapid charging target. The last 20% can take as long as the first 80%.

What are the different charger types in the UK?

A standard 3-pin plug provides about 2.3 kW. A home wallbox typically provides 7 kW. Public AC chargers are 7-22 kW. Rapid DC chargers range from 50 kW to 350 kW. Most new EVs can accept 100-150 kW DC charging.

Can I charge faster than my car supports?

No, the car limits the charging rate to its maximum acceptance rate. A car that accepts 50 kW maximum will only draw 50 kW even from a 350 kW charger. Always check your car's maximum AC and DC charging rates.

Is it cheaper to charge at home or at public chargers?

Home charging is significantly cheaper, typically 7-10p per mile versus 15-25p per mile at public rapid chargers. Home overnight rates on EV tariffs can be as low as 7p/kWh compared to 60-80p/kWh at some public rapid chargers.

Is it worth getting a home wallbox charger?

A home wallbox (7 kW) charges about three times faster than a 3-pin plug (2.3 kW). A typical EV charges overnight on a wallbox but takes 20+ hours on a plug. The £800-1000 cost is offset by cheaper overnight electricity rates and convenience. The OZEV grant may cover part of the cost.

CarCalcs

Charging Time Calculator

Calculate how long it takes to charge an EV at different power levels.

Battery Capacity

Battery capacity in kWh

Charger Type

Charger type

Current Charge

Current charge as a percentage

Target Charge

Target charge as a percentage

How We Calculate This

This calculator estimates charging time based on battery capacity, charge level, and charger power.

The Formula

Energy needed = Battery capacity x (Target % - Current %) / 100
Charging time = Energy needed / Charger power
Above 80%: Effective power reduced by 30% to account for tapering
Estimated miles = Energy added x 3.5 mi/kWh (average efficiency)

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.