What causes the E3 error on Panasonic batteries?

Error code E3 points to a communication fault between the battery and the bike's motor controller.

The BMS (Battery Management System) blocks the battery as soon as it detects an irregularity. Often the battery itself is technically sound, but the internal protection logic stays locked.

KWS Seuren investigated this in depth and found that the fault was not in the cells or the software, but in the electronic control of the communication signal.

The KWS solution: a reset function built into the battery

After extensive measuring and testing, KWS developed a hardware reset function that is built directly onto the battery's circuit board. The battery can be reset through a small hole in the casing, without taking it apart and without risk of damage. Since 3 November 2021, every Flyer and Gazelle battery repaired at KWS has been fitted with this permanent E3 solution as standard. That stops the E3 fault from coming back.

KWS Seuren: looking beyond the cell replacement

At KWS Seuren the work is not only about replacing cells or clearing error codes.

The team gets to the bottom of every problem:

  • Analysis of electronic components
  • Measuring the communication between BMS, display and controller
  • Developing in-house circuits and firmware modifications

This way of working has given KWS in-depth knowledge of battery electronics, from Flyer batteries to other e-bike systems and industrial applications.

“We want to understand why something goes wrong. Only then can you really fix it properly.”

Applied to several systems

KWS Seuren's expertise goes further than the Flyer E3 reset.

On other brands and systems, too, communication problems and electronics faults are solved for good, such as:

  • Display communication (CAN and UART repair)
  • Communication between motor and battery
  • Charge indicators that show the wrong status
  • Cell measurement and protection in the BMS


With this broad knowledge, KWS offers solutions that extend the life of batteries and make e-bike systems more reliable.

Where the solution came from

When KWS Seuren developed the E3 reset in 2021, we knew of no comparable method. The solution comes out of our own research and documentation, and it is the basis for the electronics work we now do on other batteries as well.

Summary

  • We developed the Flyer E3 reset ourselves, in 2021
  • A permanent solution instead of a temporary reset
  • Built on our own measurements of the electronics and the communication
  • Can be applied to several brands and systems

It shows what a lasting fix needs: understanding the fault first, then precise workmanship.