Update!
Yesterday i had my battery in the N1S for about 10 hours and took it in for the night in the evening. The ECU still showed only 1% in the app.
Today after i plugged the battery in the ECU suddenly jumped to 63%. I don’t know how frequently the app checks the ECU status but it does not appear to be as frequent as the other stats in the app.
I’m glad it finally worked. If you have the same kind of problem. Try to charge the ECU a longer period of time. The unplug battery and plug it in again. I hope it works for you too. 🙂