Bosch eBike batteries must never be opened- not even if they are being repaired by third parties. Opening the battery always means interfering with the condition that has been approved by Bosch and introduces safety-related risks. There is a risk that the Bosch eBike battery, once opened, may catch fire during reassembly due to crushed or incorrectly routed cables, detached components, or poor quality electrical connections due to a short circuit.
After opening, the seal of the housing can no longer be guaranteed, so the ingress of water or dust can lead to damage to the monitoring electronics (Battery Management System) or to the cells. Here, too, there is a risk that the Bosch eBike battery could catch fire due to a short circuit. These dangers also exist at a later point in time if an eBike battery, once opened, is used again.
For safety reasons, rechargeable batteries must generally satisfy the requirements of EN50604-1 and UN-T 38.3 if they are to be transported commercially. The test schedule according to UN-T 38.3 entails various safety tests on a prescribed number of rechargeable batteries that push the test specimens to their limits. Tests include, for example, overload tests, vibration, thermal tests, etc.
Even the simple replacement of original battery calls with apparently identical individual cells as part of a repair poses a threat to safety-relevant components. This would necessitate re-testing according to the safety test regime described above, however, these tests cannot be carried out on individual repaired batteries.