E-bike batteries and motors in hot weather: What e-bike riders need to bear in mind in the height of summer

Conclusion from the BIKE editorial team

When it’s hot, it’s not just our bodies we need to look after. Your e-bike can also play up in the height of summer – and that can really spoil the fun of a ride. But if you know the right tricks, you can still enjoy your mountain rides on an e-MTB, even on really hot days.

Summertime is trail time! When the sun is beating down, many of us are drawn to the open air on two wheels. But extremely high temperatures take their toll not only on you, but also on your e-bike. The battery, motor, brakes and your own body are all working at their limits in the height of summer. To help you and your bike get through the heatwave in good shape, we’ve put together the most important tips for your summer ride.

Derating – or when the electric drive starts to falter

E-bike motors and batteries have a built-in protection mechanism. If the temperature of the electronics rises above a set value, the system reduces power or switches off completely. This is done to prevent damage to the components. When the motor is working hard, the battery and motor heat up. This happens even in cool temperatures. The problem is that when it’s hot outside and the system starts with a core temperature of 40 degrees, the components don’t have much margin left before reaching the critical temperature limit. The cut-off point is reached much more quickly.

These tips will help you protect your motor and battery

Never leave your e-bike and battery in direct sunlight or in a hot boot. Find a shady spot when taking a break. In extreme cases, you may not even be able to switch on your e-bike after leaving it in the sun for a while. Please note: When the outside temperature exceeds 35 degrees, the actual temperature in a sunny, sheltered spot can be significantly higher. The same applies to the boot if the car is parked in the sun.

​Don’t transport it in the scorching heat: if you’re transporting your e-bike on the rear rack of your car, remove the battery and stow it in the air-conditioned passenger compartment.

​Charging correctly: Never charge the battery straight after a hot ride! Let it cool down to room temperature first, either in the shade or in a cool room. Similarly, the battery should not be charged in direct sunlight. Bear this in mind when planning your ride. The midday stop at the mountain hut after the steep climb may not be suitable for a full charging session. Avoid the hottest part of the day by taking a longer break in the shade for both you and the battery.

​The right cadence: Don’t put a strain on the motor by cycling at too low a cadence (‘being lazy with gear changes’). A higher cadence (approx. 70 to 90 revolutions per minute) takes the strain off the motor, allows it to run more efficiently and prevents overheating.

Moderate assistance mode: On long climbs, it’s best to shift down a gear and use Eco or Tour mode. Save short bursts of turbo power for the really nasty steep sections. This conserves both the battery and the motor.

​Adjusting your route: Make the most of the cool morning or late evening hours. Plan your route so that it takes you through shady woodland wherever possible, and avoid long climbs in the blazing midday sun.

The human body in heat mode: how to stay at your best

Your engine does help you out, but the heat still puts your circulation under extreme strain. You need to take that into account as well.

Drink before you feel thirsty: don’t wait until your mouth feels dry. Take two large bottles or a hydration pack with you. Tip: Add electrolyte tablets to your water to immediately replace the salts lost through sweating.

Sun and heat protection: Thin, breathable technical clothing protects against UV radiation and keeps you cool through evaporation. Don’t forget to cover your neck and forearms with water-resistant sun cream rub in. Under the helmet, a light layer helps Functional bandana to prevent sweat getting into your eyes.

Adjusting your route: Make the most of the cool morning or late evening hours. Plan your route so that it takes you through shady woodland wherever possible, and avoid long climbs in the blazing midday sun.