Recently I have observed an abnormally fast discharge rate of my Airnote’s battery after the disconnection of the 5 V USB external supply, as shown in the attached screenshot:
Within about 5 h from the 5 V removal the battery voltage dropped down to 3.5 V
As shown in the following screenshot, the 5 V USB wall-plug supply remained connected during the last 18 days, hence I expected a fully charged battery ensuring a very long working time.
Is there something wrong with the battery? In case I could replace it.
Thank you very much and best regards,