1
Open Device Manager (accessible by right clicking your Start Button)
Expand the Batteries section
For each device in that section:
Right click and choose Disable
Wait a second or two, then right click and choose Enable
Close Device Manager
Restart (not shut down) your laptop and check if the Battery icon is back on the taskbar and if your battery is charging correctly.
2
If that does not resolve the problem, start your laptop, then, as soon as you see the Dell logo, repeatedly press the F12 key.
On the resulting menu, select Diagnostics.
Run that full diagnostics test, does it find any problem with the battery or the power adapter.