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Unallowed product tying with e-bike batteries

Published: 04 April 2019
Last updated: 04 January 2023

Electric bicycle manufacturers do boycott aftermarket batteries

At electric bicycles, only a battery of the own brand can be used, that is product tying and is prohibited. If the same existed for cars, the 12V battery could not be replaced by any other battery, which is of course very undesirable. 

The sale of batteries is an important revenue model for electric bicycle manufacturers. Therefore almost all e-bikes use special software that blocks the motor when another battery is detected, while in principle every battery is usable. That is why there is no secondary market for batteries for the major brands of ebike motor manufacturers such as Bosch, Yamaha and Shimano.  

Communication with the battery

An e-bike motor has to communicate with the battery to determine the state of charge. That is why a battery not just has a + and - cable but also one or more communication cables. This communication is not standardized. Every manufacturer uses its own system. Used are for instance I2C or CAN bus. But the communication is also used to detect if an own brand battery is connected. If only the + and - cable is connected, without the communication cables, the system will not work. A battery must have the same communication as the original battery. Often this cannot be copied because encrypted battery authentication, for instance SHA-256 is used.

Only Yamaha doesn't use encrypted authentication and it is possible to use another battery, this requires a special dongle, see here.

Forbidden product tying with e-bike batteriesForbidden product tying with e-bike batteries

Brand-batteries are expensive and have poor quality

For battery replacement, people are forced to buy a battery of the same brand as the bike, they have no choice. But these batteries are expensive and, moreover, usually of poor quality. While the battery of an electric car has a lifespan of more than 8 years, a bicycle battery barely lasts 3 years. The sale of own brand batteries is an important revenue model for electric bicycle manufacturers. Product tying is not allowed according the European Union competition law.


  • I want to bring about that these tying will be get prohibited.
  • EU has banned similar practices of Windows and Google.
  • There is an effective aftermarket in the automotive industry and it is also regulated: Block Exemption Regulation.

More and more people are buying ebikes, but the poor quality of the batteries is a major frustration for them. Better and cheaper batteries will be available in a free market of e-bike batteries.

Autoriteit Consument en Markt (ACM)

I have informed the Autoriteit Consument en Markt (ACM) about the product tying, they are now investigating this.

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