You want to store your e-bike battery. The only question is: how? Do you need to protect the battery from frost, or not? Is it better to store it on the e-bike or in the apartment? Should the battery be charged to 20%, 50%, or 90% for storage? There are always rumors and suggestions that contradict each other. We clear up misinformation and well-intentioned but incorrect advice!
Here you will learn how e-bike batteries and displays should be stored so that they are not damaged. How to store the “rest” of the e-bike can be found in another article. And these tips are especially valid for winter and frost. If you store your e-bike at another time of year (for a trip or the recovery phase after an injury, for example), it should be clean and well-lubricated, but you can easily store the battery on the bike! In any case, you should take a look at the user manual before storing your e-bike. There you will usually get tips for your device directly from the manufacturer. These manufacturer instructions are of course always the top priority!
Storing an E-Bike Battery - Here's How!
Even if you normally don’t remove the e-bike battery because it can be charged on the bike, you should grab the key for the battery compartment before winter and take the battery inside. Most external e-bike batteries are secured with a lock. Integrated batteries are located behind a locked flap in the frame of the e-bike. So – just unlock and take the battery with you!
If you ride your e-bike in the winter, you should still store the battery indoors overnight, during work, or on the weekend.
Somehow an e-bike battery can usually be removed so you can store it! Image © Trek
You can then store your e-bike battery in a cool, dry room. You should NOT leave it connected to the charger during storage!
At What Temperature Should an E-Bike Battery Be Stored?
Batteries and accumulators do not like extreme temperatures, neither heat nor cold.
The best storage temperature is between 10 and 20 degrees Celsius, which is rather cool but not cold. So, in a heavily heated room, the stored e-bike battery will not feel quite comfortable.
There is still a rumor that a battery must always be fully charged, then completely discharged, and then fully charged again. Manufacturers today recommend a different approach. You can always fully charge the e-bike battery, but completely using up the charge is not recommended.
At what charge level should you store your e-bike battery?
One of the largest manufacturers of e-bike drives recommends: If you want to overwinter your bike battery, you should do so at a charge level between 30 and 60%.
If your e-bike battery shows more charge, it is a good opportunity for a farewell round before storage. If it is less, you can simply recharge it a bit. It is also advised to check the charge level from time to time during a multi-month storage, even if newer batteries generally no longer self-discharge (more information on self-discharge can be found further down).
The rumor still persists that a battery should always be completely charged, then completely discharged, and then fully charged again. Manufacturers today recommend a different approach. You can always fully charge the e-bike battery, but it is not advisable to use up the charge completely.
Do I have to store my e-bike and battery in winter?
We explain here how you can store your e-bike and battery in winter. But you do not have to store it; of course, you can also use your e-bike throughout the winter. This generally does not harm a good e-bike! You should just clean and lubricate it from time to time according to our maintenance instructions, so it usually survives winter use undamaged.
The only difference from a bio-bike: Take the battery and display inside your home or to the office on cold days. You don't have to remove both devices at every store during a shopping trip, but a longer cold period does not do them any good. There are suitable neoprene covers that insulate the battery for the way home or short trips. They also protect the device from road salt and moisture.
For longer idle times, you should remove your battery and bring it inside in winter, even if you use the e-bike daily. Image ©Trek
Not only the e-bike battery is sensitive to cold, but some displays also do not handle frost well. If the e-bike display can be removed, you should do so for the storage period. It is then usually with batteries operated, you should remove them so they don't leak in the device. If it cannot be removed, you don't have to worry about it breaking immediately. It will then probably be operated via the e-bike's battery and at least doesn't have its own batteries or accumulators that could cause trouble.
Not only should the battery be stored at mild temperatures, but the display should also be removed if possible. Image © Winora
The e-bike battery has less range in winter
If you ride your e-bike in winter, you will probably notice that it has less range than in summer. In freezing temperatures, the capacity of a battery decreases, as the processes that power your device are significantly slowed down. By the way, this is not only the case with e-bikes, your phone reacts similarly to cold! You should consider this when planning tours.
The self-discharge of the stored e-bike battery
You might remember the problem from your Walkman batteries “from back in the day”: You left the fully charged device in the corner and didn't use it for a while. Yet the batteries eventually ran out. When a battery-powered device is stored for an extended period, batteries and accumulators slowly lose some charge, even if it hasn't been used. The longer the storage lasts, the less residual charge is potentially available. This effect is called “self-discharge.”
The real problem with self-discharge is not the empty battery, but the deep discharge. When your e-bike battery indicates it wants to be charged, there is always a certain residual voltage present. However, it must not be undershot, and that's exactly what would happen with a deep discharge. Depending on the battery type, a deep discharge can damage the battery. For this reason, batteries should be stored with a charge of 30 to 60% and the remaining charge level should be checked from time to time during storage. Most batteries have an integrated charge level indicator that reveals how much charge is left at the touch of a button. If it drops, you should also recharge a bit during storage. Leaving the charger connected during storage is not a good idea!
The charger must not remain plugged into the stored e-bike battery for days or even months! Image © Trek
And the good news is: With modern batteries – as well-known brand manufacturers assure – this effect hardly plays a role anymore. So if you want to store your e-bike battery over the winter, you usually don't have to worry that it will be completely empty in the spring, but occasional checks won't hurt. If you suspect that your battery is deeply discharged because it can no longer be charged, you should check with the manufacturer or a bicycle workshop.
And where to put the rest of the e-bike?
We have a blog post for you that tells you exactly how to prepare your bicycle or e-bike for long-term storage. You should read it if you want to park your bike for a while! Since without a drive and battery it is more or less just a bicycle, the same rules apply to an e-bike as to how a regular bicycle is wintered.
Here is a brief summary:
- Wash the bicycle thoroughly.
- Once it is dry, you should lubricate it well.
- Store it in a dry place. A frost-free location without direct sunlight would be ideal.
- If you store your e-bike without a battery and display, you should keep the contacts dry and clean.
- Lock your bicycle securely.
You should also store the e-bike battery charger carefully!
At first glance, this advice may seem unnecessary. But the charger is an important part of your e-bike, nothing works without it! Many e-bikes weigh between 25 and 30 kilograms, without the drive they are difficult to move. You don't want to suddenly face the problem that you can no longer charge the – actually intact – e-bike! And a new charger is expensive, especially if you have a speed charger, a particularly fast charger for your e-bike battery.
- You should definitely store your battery charger dry so that the contacts do not rust.
- The plug contacts should also be kept clean so that you don't push dust or abrasive particles into the e-bike's charging socket. Small grains can scratch the contacts over time or even wear out the charging socket until the plug no longer holds.
- The cables must not be kinked when you wrap them around the power supply box for storage.
- If the e-bike battery is fully charged – unplug!
- If you don't use your e-bike over the winter, you should also bring the charger inside and not leave it in a damp, cold garage at sub-zero temperatures.
It is also advised against replacing the original charger with an aftermarket device! Inferior chargers often have numerous defects, charge with the wrong voltage, or generate so much heat that they set their base on fire and the like.
If the battery was stored incorrectly
If your battery has significantly lost range after the winter or no longer works, it must be replaced with an identical battery . It's best to replace a defective e-bike battery with an original spare part from the bike or drive manufacturer, so you can be sure that it fits your motor.
Overwintering the bike battery without problems…
… is not as difficult as you can see. With these tips, your e-bike will get through the winter rest period well and unharmed. However, it doesn't hurt to "wake up" your e-bike after a long storage period, thoroughly check it, and fully charge the battery.
You can also find more tips for a good bicycle winter here in the blog:
- Cleaning and maintaining the bike: Clean through the winter in 5 steps
- Cycling clothing for winter – the best frost protection
- Winter with the bicycle – finally safe through ice and snow!
- Everything you need to know about bicycle storage
- Charging the e-bike battery – here's how
Title image: KBO on Unsplash
