It seems Battery charging is a common issue for all the tabs, I had faced similar issue for my Yoga tab 3 also.
Had tried online solutions and Service engineer visit also unable to resolve the issue, until I find the resolution myself as below.
Actual issue is here:
Go to '''Battery''' options on your Device settings.
You can see the Battery charging mode, shows as ‘USB’ charging.
The device can able charge through AC power adapter only, hence unable to charging on USB charging selected.
Resolution:
Remove the USB connector from the Tab device and AC adapter from wall power outlet (Must need to remove both the ends).
Reconnect the USB cable and AC adapter to wall unit. Now check the charging mode, it shows '''charging with AC.''' Now the device can charge as normal condition.
Note: If Battery charging shows USB charge, you have to do this step again by disconnect the ports and reconnect until you see the AC charging mode for Battery.
Hope your issue got resolved, try same method all Tab models and smart phones having battery charging issue.
- Bangarubabu