Range is the first number most people look at, and the one most often misunderstood. A brochure figure of “up to 80 miles” is usually measured in ideal conditions on the lowest assistance level. Here is how to work out what you really need.
Start with watt-hours, not miles
A battery’s capacity is measured in watt-hours (Wh). It is the most honest way to compare bikes, because it does not depend on how the manufacturer tested the range.
As a rough guide, mixed city riding with moderate assistance uses somewhere between 10 and 20 Wh per mile. So a 500 Wh battery gives roughly 25 to 50 miles on a light city e-bike, and more if you ride gently on flat roads.
Heavy full-suspension fat-tyre e-bikes use noticeably more. For example, the manufacturer of the RANDRIDE YX80M-2 estimates 31 to 60 km (about 19 to 37 miles) from its 960 Wh battery, which works out at roughly 26 to 50 Wh per mile. That is the manufacturer’s estimate and has not been independently tested. The manufacturer of the YX90M has not yet supplied a range estimate, so we do not quote one. Always compare the manufacturer figure with your own longest regular ride.
An illustrative range table
Range in miles is roughly the battery’s Wh divided by the Wh used per mile. The figures below are simple arithmetic to show the effect of riding conditions, not test results for any bike.
| Battery | Gentle riding, light bike (15 Wh/mile) | Mixed riding (25 Wh/mile) | Heavy bike, hills, cold or high assistance (40 Wh/mile) |
|---|---|---|---|
| 400 Wh | about 27 miles | about 16 miles | about 10 miles |
| 500 Wh | about 33 miles | about 20 miles | about 13 miles |
| 672 Wh | about 45 miles | about 27 miles | about 17 miles |
| 960 Wh | about 64 miles | about 38 miles | about 24 miles |
Why manufacturer estimates vary
There is no single mandatory range test for e-bikes, so brands measure in different ways. Quoted figures are usually reached on a low assistance level, on flat ground, in mild weather and with a light rider. Two quoted ranges are therefore rarely comparable, which is why battery Wh is the better starting point.
What changes your range
- Assistance level: the biggest factor. Turbo mode can halve your range compared with eco.
- Hills and headwinds: climbing asks much more of the motor.
- Weight: rider, luggage and children on the back.
- Stop-start riding: pulling away from every junction uses more energy than cruising.
- Cold weather: lithium batteries deliver less in winter. Expect noticeably shorter range on frosty mornings.
- Tyre pressure: soft tyres roll less easily. Check them every couple of weeks.
Work out your number
Take your longest regular day, for example a 9 mile commute each way plus a detour to the shops: about 20 miles. Add 30 to 50 percent for winter, wind and the day you forget to charge. That gives you a target of 26 to 30 miles in real conditions. On a light city e-bike, a 400 to 500 Wh battery covers that comfortably; a heavy fat-tyre bike needs a much larger battery for the same distance.
Our commute calculator turns your daily miles into yearly mileage, number of charges and electricity cost, with every assumption shown.
Charging
E-bike batteries charge from an ordinary household socket, usually in 3 to 6 hours from empty. A removable battery lets you charge it at your desk or in the kitchen without bringing the whole bike indoors. For long battery life, avoid leaving it completely empty for long periods and store it indoors in winter.
Do not overbuy
A bigger battery adds weight and cost. If you live in a flat up two flights of stairs, a lighter bike with a smaller battery you charge twice a week may suit you better than a heavy long-range model. Our Bike Finder weighs range against weight and storage for you, and our comparison page sets the two RANDRIDE batteries side by side.
This guide is general information for riders in the UK. Rules and product details can change, so check GOV.UK and each bike's specifications before you buy.