iPad Air iOS 12.4.6 shows 100% charged while plugged in, unplugged goes completely empty and unusable
My iPad Air model MD785B/B iOS 12.4.6 is unusable away from a charging point.
When the iPad charging cable is plugged into a power source, the battery meter shows 100% powered and I can use the device normally.
When I unplug the charging cable and try to use the iPad as a mobile device as intended, , it operates normally for a short while while the battery meter still shows 100% charged.
When normal usage (web browsing etc) whilst not connected to power makes the charge level naturally drop below 100%, however, the screen immediately goes black. Pressing the Home button receives no response - black screen.
Pressing the power button at the top right of the device shows the Empty Battery icon and the icon telling me to plug the charging cable in. Therefore I can't use it anywhere except near an electrical or USB socket.
Internet research suggests this might be solved by calibration between the battery meter software software and the true physical charge state of the battery.
Can I resolve this myself somehow without returning the device physically to an Apple Store, as we are in midst of a pandemic lock-down and this is obviously not possible? For the same reason, it would be really beneficial in these strange times to have an iPad right now for reading eBooks and Comics away from a charging point, as God, or at least Steve, intended. Thanks.
iPad Air, iOS 12