This UK planning example budgets a full week of public backup charging for someone without a home charger. It uses 150 miles a week and an assumed 3.5 miles per bought kWh, including charging losses. The efficiency is a planning input, not a measured result for a named car.
| Public energy price | Energy bought | Weekly energy cost | Annualised energy cost (52 weeks) |
|---|---|---|---|
| 50p/kWh (illustrative) | 42.86 kWh | £21.43 | £1,114.29 |
| 59p/kWh (Braintree standalone AC example) | 42.86 kWh | £25.29 | £1,314.86 |
| 85p/kWh (Braintree DC example) | 42.86 kWh | £36.43 | £1,894.29 |
Calculation: 150 miles ÷ 3.5 miles/kWh = 42.86 kWh/week (rounded for display); cost = unrounded energy × tariff. Energy only: parking, idle, subscription, detours, and vehicle finance are excluded. The Braintree listing states 24/7 access; check live connector price, availability, parking rules and facilities before a trip. A charger’s maximum power does not predict your session time.
Sources: GRIDSERVE Braintree Electric Forecourt (checked 8 October 2026) · GRIDSERVE pricing and connector conditions (checked 8 October 2026) · Energy Saving Trust: charging electric vehicles (checked 6 October 2026)