Is your e-bike battery flat? These factors affect your e-bike’s range

Manufacturers’ specifications for e-bikes often promise ranges of 120 kilometres or more. Yet after the first climb, the display suddenly shows only 30 kilometres remaining. Why is there such a huge discrepancy between expectation and reality when it comes to e-bike batteries? The short answer: range is not a fixed value, but the result of the interplay of many factors. If you want to accurately estimate the range for your next e-bike ride, you need to understand the basics. We’ll show you which factors influence range.

Here are the 5 main factors at a glance:

1. The battery size

You can look at it any way you like. The fact is: the greater the battery capacity, the greater the range. If all other factors remain constant, this is the single most decisive factor. 800 watt-hours is the standard for modern e-mountain bikes. Some cheaper models or ‘light’ e-bikes come with significantly less capacity. Roughly speaking, you can only get half the range out of an e-bike with just 400 watt-hours.

2. The total weight (cyclist + bicycle + luggage)

The motor has to move mass. The more weight there is to accelerate uphill or when setting off, the harder the motor has to work. This can make a big difference. Rule of thumb: an extra 10 kg can reduce the range by as much as 5 to 10 per cent. The hillier or steeper the route, the greater the impact of weight. So, saving 500 grams on luggage is hardly worth the effort. However, differences in riders’ weight or carrying a lot of luggage for a multi-day tour can make a huge difference to the range.

3. The route profile

Range is often given in kilometres, but this is hardly meaningful. On flat terrain, the range in kilometres can easily be twice as high as on a steep mountain. The combination of kilometres and metres of elevation gain is crucial for route planning. Particularly for e-mountain bikers and tours in the Alps, elevation gain should be a key focus when planning your route and battery usage.

The surface can also have a significant impact. Tarmac places little strain on the battery. Gravel, sand or even deep mud increase energy consumption dramatically.

4. The level of support

This factor is particularly important because it’s entirely up to you! If you ride constantly in ‘Turbo’ or ‘Boost’ mode, you’ll use an enormous amount of power. The result: the battery runs out faster – and you, as the rider, have less time to cover kilometres or climb metres under your own power. Roughly speaking: in Eco mode, you can squeeze out twice the range compared to riding in continuous Turbo mode. Here’s a tip: progressive modes, such as Bosch’s Tour+, prevent the motor from doing all the work whilst the rider is slacking off. This effectively leads to you using your own leg power more, and thus achieving greater range.

5. The temperature

In many cases, the temperature has no significant effect on your e-bike’s range. However, there is one exception that can have a truly drastic impact. Winter, with its frost and cold, can bring your e-bike to a standstill. In the worst-case scenario, the range can drop to 50 per cent of what you’re used to. You’ll notice the biggest impact when the e-bike battery has cooled down completely – for example, if it’s been stored in freezing conditions before your ride. That’s an absolute no-go. It’s better to store it at room temperature and only fit it into the bike just before setting off.

When the engine is running, it generates heat, which also keeps the battery at operating temperature. During long breaks or when travelling downhill, the battery cools down, which also reduces the range. Whenever possible, take the battery with you into a warm place or keep it at the right temperature by using the engine.