12 questions about your eBike battery

1. What is special about lithium-ion batteries?

Vikram Godbole: Lithium-ion batteries are among the most up-to-date and common eBike batteries around. They are characterized by high mileage, low self-discharge, and long service life with low weight. Due to their high energy density, they can store a lot of energy in a small space and are quickly ready for use even after long periods of storage – without the need for lengthy recharging. That is why we rely on lithium-ion technology for all Bosch eBike batteries
 

2. What role does safety play for eBike batteries?

Vikram Godbole: Lithium-ion batteries are complex in structure, have a high energy content, and can cause dangerous situations because certain constituents are flammable. For this reason, eBike batteries must undergo extensive legally prescribed tests (e.g., leakage, overcharging, and short-circuit tests) and may only be placed on the market once they have passed these tests. Bosch eBike Systems goes beyond the strict legal requirements in some of these tests and tests the battery cells in other short-circuit scenarios in addition to the prescribed short-circuit test, for example.
 

3. What additional measures has Bosch eBike Systems taken to make eBike batteries safer?

Vikram Godbole: Safety is our top priority. That is why, along with the additional tests, we have taken further measuressafety measures depending on the design and generation to make our batteries safer and ensure consistently high quality. This starts with the selection of the battery cells that we purchase from suppliers. Here we only work with renowned cell manufacturers. They develop the cells based on our strict requirements for cell quality and safety. To ensure that this is regularly checked, we have introduced quality controls that go beyond the standard.

We have designed our batteries in such a way that the risk of a short circuit or overheating is reduced by the mechanical, electrical, and thermal separation between the battery cells. The condition of the battery is monitored by the intelligent battery management system. It detects potential fault sources and protects against excessive operating temperatures, overload, and deep discharge. In addition, the sealing concept of a Bosch eBike battery protects against water ingress and therefore against consequential damage.

The high degree of automation in the production of the smart system's batteries, including strict quality controls, also contributes to the safety of our batteries. In addition, we have our batteries assessed by accredited laboratories for compliance with the standards. For example, we have certified our entire eBike system in accordance with the strict UL 2849 safety standard. In addition, all batteries are UL 2271 certified.
 

4. What basic rules do I need to follow when handling my eBike battery?

Vikram Godbole: It is important that the battery is protected from heat, direct sunlight, and fire. In addition, the battery must not be immersed in water or cleaned with a pressure washer. If you are transporting your eBike on a car rack, remove the battery if possible. Also keep the battery away from small metal objects such as keys, nails, or screws. There is a risk of contacts being bridged, which can lead to a short circuit. Also note that the housing must not be opened. This is reserved exclusively for qualified and trained personnel. Opening the battery always means interfering with their certified condition and entails safety risks.
 

5. What is the service life of an eBike battery?

Vikram Godbole: An exact service life cannot be predicted. Your eBike dealer can determine the currently available capacity of your Bosch eBike battery using the CapacityTester. In principle, however, batteries are wearing parts. The more intensively you use your battery, the faster it ages. A memory effect, i.e., decreasing capacity due to frequent incomplete discharge, does not occur with lithium-ion batteries. However, even if you do not use the eBike battery, it will age over time. This is due to chemical reactions in the battery cells. If the battery is exposed to high temperatures or is stored at a low or high charge level, this also leads to a shorter service life. A long service life is fundamentally important to us, which is why our cell suppliers have to meet high standards.
 

6. What other aspects should I consider for storage?

Vikram Godbole: If you are not using the eBike for a longer period of time, you should remove the battery from the eBike if possible. Ideally, you should store your battery at a charge level of 30 to 60 percent and temperatures between 32 °F (0 °C) and 68 °F (20 °C) in a dry environment or between 50 °F (10 °C) and 68 °F (20 °C) in a humid environment with dew formation. The best place to store the battery is in a well-ventilated room with a smoke detector, away from heat sources or highly flammable materials. Storing the battery in a basement or garage is better than storing it in living spaces due to the cool temperatures.
 

7. What precautions should I take in winter?

Vikram Godbole: In general, cold weather reduces battery performance. During winter use at temperatures below 32 °F (0 °C), we therefore recommend bringing the battery into a heated area before setting out and waiting until it has warmed up to room temperature. If the eBike is not in use for a longer period of time – in winter, for example – the instructions for correct storage apply.
 

8. How do I charge my eBike battery correctly?

Vikram Godbole: Before charging, you should check the eBike battery for visible damage. You should also let it cool down. It is also important to ensure that your charger is compatible with the battery: please only use chargers that are compatible with Bosch eBike batteries. This helps to protect the battery from damage and hazards such as overheating or short circuits. You are always on the safe side with original Bosch chargers. When charging, the ambient temperature should be between 32 °F (0 °C) and 104 °F (40 °C) and ideally at room temperature. A dry environment with a smoke detector and without direct sunlight is also important. Whether full, half full, or empty: you can charge batteries with lithium-ion cells for as short a period as you like, irrespective of their charge level. Interruptions in the charging process do not harm the batteries. However, only fully charge the battery if it is really necessary. Disconnect the battery and charger from the power supply after charging.
 

9. How long does it take to charge my eBike battery?

Vikram Godbole: The charging time depends on the capacity of your battery and the charger used. For eBikes with the smart system, it ranges from just over an hour to approximately five hours for half a charge. To fully charge the battery, it takes between approximately three and eleven hours. You can find the exact details here: Charger
 

10. What must I bear in mind when cleaning the battery?

Vikram Godbole: If possible, remove the battery before cleaning your eBike. We recommend wiping the battery with a damp cloth. The plug poles of the eBike should also be cleaned occasionally and lightly greased with technical petroleum jelly. To protect the electronics, do not clean the battery with a direct water jet or pressure washer. You should also avoid harsh cleaning agents. They can lead to changes in the surface.
 

11. How far can I ride with my eBike battery?

Vikram Godbole: For many eBike riders, this is a key question to which there is no definitive answer. The answer can differ enormously – from less than 30 miles (50 kilometers) on a full battery charge in the smart system to up to approximately 100 miles (170 kilometers). This is because the range depends on many factors. They include the support level, riding behavior, air resistance, the rider's weight, tire pressure, and, of course the terrain. Our range calculator allows you to estimate a typical range under various parameters. You can find out how to optimize your range, for example, in our Help Center.
 

12. How do I dispose of my eBike battery?

Vikram Godbole: Once your battery has reached the end of its service life, it must be disposed of properly. For safety reasons, you should have defective, old, or used batteries properly recycled. You may return old batteries to a local bike shop. Find a drop-off location here. www.hungryforbatteries.org There they are collected by authorized battery collection systems and sent for recycling. Almost 71 percent of raw materialsSource: Gemeinsames Rücknahmesystem Servicegesellschaft mbH (2023): "Nach­hal­tig­keit durch Rücknahme von Altbatterien aus E-Bikes und anderen elektrischen Kleinfahrzeugen steigern" (Increasing sustainability by taking back used batteries from eBikes and other small electric vehicles), presented at Eurobike 2023. in a used eBike battery can be recovered and used for new products.
 

More information and tips on handling the battery can be found in the Battery Guide.
 

About Dr. Vikram Godbole

Dr. Vikram Godbole holds a doctorate in electrochemistry with a focus on lithium-ion cells and has been working as a battery expert at Bosch eBike Systems for over ten years. He is currently Senior Product Manager for batteries and chargers and is responsible for defining new eBike batteries and chargers. In his free time, Vikram likes to get out and about on two wheels – both on his touring bike and on his motorcycle.