ST7 - cannot be switched on

In spedepedelecreview.com the user writes Lankram:

I have discussed this with my dealer. The cause lies in the battery. The system needs 10 V to start and this is obviously not being passed on somehow. By connecting the charger, the 10V is available again and the bike works again. My dealer advised me to keep an eye on it (how could I miss it, haha). In any case, have it noted in the system that this is happening. My advice is to report this to your dealer as well. I don't have an error code displayed on the screen, do I? And take your charger with you, as you won't be able to open the battery compartment without it and it will be a walk in the park. Regards Markus

Unfortunately, no solution has been published. I suspect that the problem may have been caused by a dirty battery socket or a metal particle.