Your e-bike battery in the winter months

Before you set off, check that the battery has enough charge. You need it for your range, and also for the lights on your e-bike, which you rely on to be seen in the dark winter months. If your lights run on separate batteries, take spares with you or replace them in good time. Bear in mind that cold can reduce the capacity of a battery considerably, and that cuts your range.

Do you ride through wind and weather all winter, or does your e-bike (and its battery) go safely into the shed? Either way, the battery needs looking after. With these tips you prevent damage to your e-bike battery over the winter.

There is a misconception that lithium batteries are better left unused and uncharged in winter, for fear of damage. The opposite is true: not using or charging these batteries can lead to a far more serious problem, deep discharge. Deep discharge happens when a lithium battery sits idle for a long time and drains completely, down to a level at which people often wrongly assume the battery can no longer be charged and is therefore useless.

At KWS Seuren we recover lithium batteries that have been deeply discharged. With the right equipment we can often bring them back to life. Whether that works depends on how deeply and for how long the battery was discharged, and the intake test shows that.

• Keep the battery indoors at room temperature and fit it just before you ride.
• Expect less range in the cold, and choose a lower assistance level if you need to get home.
• After a ride in the cold, let the battery warm up to room temperature before you charge it.

• Take the battery out of the bike and store it somewhere dry and frost-free.
• Do not put it away empty: a charge of 40 to 60% is best for storage.
• Check the charge once a month and top it up if needed.

1. Charge the battery regularly, even when it is not completely empty, and keep the charge between 20% and 80%.
2. Use a protective cover for the battery in low temperatures.
3. Always read your battery's manual for specific storage advice.
4. Always keep an eye on the battery while it charges, and disconnect it as soon as it is charged.

How cold can a battery get?

Several brands and types of battery switch off below 5°C. They do this to prevent damage. The battery may not start up in the bike. It may also refuse to charge.

Can I use my e-bike battery in extremely low temperatures?

You can use an e-bike battery in extremely low temperatures, but bear in mind that the cold can affect the performance and the life of the battery.

Does winter affect the life of my e-bike battery?

Yes, winter can affect the life of your e-bike battery. Lithium-ion batteries, which are widely used in e-bikes, are sensitive to extreme temperatures, both cold and hot. At low temperatures the chemical reaction in the battery can slow down, which affects its performance and its life. Long exposure to cold, especially when the battery is not charged and looked after properly, can reduce its capacity and shorten its life. So store and look after the battery properly during the colder months.

How does cold weather affect the performance of my e-bike battery?

Cold weather can affect the performance of your e-bike battery considerably. At low temperatures the internal resistance of the battery rises, which means less capacity and a shorter range. The chemical processes inside the battery slow down, so the battery delivers energy less efficiently. You may cover fewer kilometres on a full charge. Charging can also take longer, and you should avoid charging the battery in very cold conditions, because that can shorten its life. An insulated cover keeps the battery warmer and limits the effects of the cold.

Can an e-bike battery cope with the cold?

Yes, in principle an e-bike battery can cope with the cold, but there are a few things to keep in mind. E-bike batteries, most of them lithium-ion, are designed to withstand a certain amount of cold. At extremely low temperatures they can become less efficient.

How do I store my e-bike battery in winter?

The best way to store your e-bike battery in winter is with a charge of between 40% and 60%. That preserves the life of the battery. Choose a storage place that is cool and dry, and avoid places where the temperature can drop below freezing. Check the battery regularly and, if necessary, top it up to the recommended storage charge. For long-term storage, take the battery out of the bike. That extends the life of both the battery and the bike.