Thomas — Daily commuter, Bristol
10 miles each way, 5 days a week
- Battery
- 500Wh
- Charges per week
- 2×
- Cost per charge
- 15.4p
£16.02 / year vs £1,200/yr bus pass

Short answer
Charging an e-bike battery uses very little electricity. A typical battery holds 0.3 to 0.75 kWh, and a full charge takes about 3 to 6 hours on a standard charger. Charging overnight on an Economy 7 tariff cuts the cost per charge by 30 to 40 percent, and commuters covering 40 to 60 miles a week usually charge once or twice a week.
The formula: Battery Capacity (Wh) = Voltage (V) × Amp-hours (Ah)
Example: 48V × 13Ah = 624 Wh • 48V × 25Ah = 1,200 Wh
Convert battery capacity to kWh
Divide your battery’s Wh rating by 1,000. A 500Wh battery becomes 0.5 kWh; a 624Wh battery becomes 0.624 kWh.
Apply a charger efficiency multiplier
No charger transfers energy with perfect efficiency. Using 1.2 as a practical middle ground: Adjusted energy draw = Battery capacity (kWh) × 1.2
Multiply by your electricity tariff
Using the Ofgem price cap rate of 25.73p/kWh: a 500Wh battery costs 15.4p per full charge; a 624Wh battery costs 19.3p.
The standard unit rate under the Ofgem price cap currently sits at 25.73p/kWh, with most flat-rate tariffs in 2025–2026 hovering between 25p and 28p/kWh.
| Battery Capacity | Energy Drawn (×1.2) | Cost at 25.73p/kWh | Cost at 27p/kWh |
|---|---|---|---|
| 300 Wh | 0.36 kWh | 9.3p | 9.7p |
| 400 Wh | 0.48 kWh | 12.4p | 13.0p |
| 500 Wh Common | 0.60 kWh | 15.4p | 16.2p |
| 624 Wh Common | 0.75 kWh | 19.3p | 20.2p |
| 750 Wh | 0.90 kWh | 23.2p | 24.3p |
| 1,200 Wh | 1.44 kWh | 37.1p | 38.9p |
Cost per mile: A 500Wh battery delivers roughly 40–60 miles of UK range. At 16p per charge, that is approximately 0.27p–0.40p per mile — compared to 12–20p per mile in fuel costs for a petrol car.
For most standard UK e-bikes, a full charge from empty takes between 3 and 6 hours.
2A — Travel / Compact
3A — Standard (most common)
5A — Fast Charger
Standard flat-rate tariffs run 25–28p/kWh. Economy 7 off-peak rates drop to 17–20p/kWh between 10pm and 8am. Charging a 500Wh battery overnight at 17p/kWh costs approximately 10.2p — saving around 6p per charge.
| Rider Type | Weekly Mileage | Charges per Week |
|---|---|---|
| Occasional leisure rider | 10–20 miles | Once every 1–2 weeks |
| Standard commuter | 40–60 miles | 1–2 times |
| Heavy commuter / cargo user | 100+ miles | 3–5 times |
| Rider Profile | Battery | Charges / Week | Monthly Cost | Annual Cost |
|---|---|---|---|---|
| Weekend leisure rider | 500 Wh | 1 | ~67p | ~£8.00 |
| Standard commuter | 500 Wh | 2 | ~£1.34 | ~£16.00 |
| Regular commuter | 624 Wh | 3 | ~£2.51 | ~£30.10 |
| Heavy daily user | 500 Wh | 7 | ~£4.68 | ~£56.20 |
Even the most intensive scenario — charging every single day — produces an annual electricity bill of around £56. Less than a single tank of petrol in most family cars.
| Transport Mode | Annual Energy / Fuel Cost | Cost Per Mile | Additional Costs |
|---|---|---|---|
| E-bike | £8–£56 | 0.27p–0.40p | No road tax, no MOT, no mandatory insurance |
| Petrol car | ~£1,300 | 12p–20p | Insurance, road tax, MOT, servicing |
| Electric car (home charging) | ~£12.87 per 50kWh | 4p–6p | Insurance, road tax, servicing |
| London Underground | ~£3,600/yr | — | — |
Key habits:
Thomas — Daily commuter, Bristol
10 miles each way, 5 days a week
£16.02 / year vs £1,200/yr bus pass
Amir — Food delivery courier, London
Full battery drain most days, Economy 7
£38.10 / year total charging overhead
Davies family — Cargo bike, Sheffield
School runs and shopping on hilly terrain
£50.54 / year less than two tanks of petrol
Weekend trail rider — Wales
Full day on trails, once per week
£12.64 / year less than a cinema ticket
The Bottom Line
Charging an E-Bike Is Measured in Pennies
A single full charge costs 9p–37p. A standard commuter’s annual electricity bill sits comfortably below £30.
No. A typical e-bike battery holds 0.3–0.75 kWh. A standard tumble dryer consumes around 1.5 kWh per hour — you could fully charge most e-bike batteries for the energy cost of half a dryer cycle.
Modern e-bike batteries include a BMS that automatically cuts charging current at 100%. That said, it is good practice to unplug once charging is complete rather than leaving it connected indefinitely.
Yes, provided you use the manufacturer-approved charger and charge in a well-ventilated room away from flammable materials. Avoid charging on soft surfaces such as sofas or beds. A smoke alarm in the charging room is a sensible precaution.
No. A fast charger draws more watts but completes the cycle sooner. Total energy delivered in kWh is the same, so your electricity bill is unaffected.
For most UK commuters covering 40–60 miles per week, once or twice a week is sufficient. A standard 500Wh battery provides 35–70 miles of real-world range depending on terrain, assist level, and rider weight.
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