Hi again,
I have several updates and new questions for your expertise, if anyone could help:
Several examinations were held:
1. When connect to power supply (charger or PC USB) the battery is charged for several seconds (the voltage is constantly dropping from about 4V to stopped charging).
2. Several other batteries 3.7V with less capacity were tried, but the result is the same - after several seconds the charging simply stops

3. The battery was completely removed and then measurements has been executed without battery to see the result... And it was surprising! If a battery is not presented then the Aura HD provides constant charge of about 4V!
4. If a battery is installed back then immediately the charge is dropping and completely stopped in seconds!
Does anyone know if the Kobo Aura HD has any kind of chip that detects, if the battery is not original and if it is not - then stops the charging? Or do you know if the other Kobo devices has such detection for non-original battery?
Do you know how can I bypass this potection, if it really exists?
Maybe it is possible the cause to be some misbehaving chip that does not like batteries at all

... I am running out of ideas
Could anyone give some ideas how to proceed further please?
Thank you very much

and