Please list exact Dell model number and version of windows. Ex: Dell Inspiron 3543, windows 10
In the meantime, right click the battery icon, click on Dell Command | Power Manager, and then check Battery Health. Is the battery health listed as operating normally or Excellent ? Is the battery setting listed as Adaptive, see image below)? Does the computer operate without AC adapter plugged into system?
Type msinfo32 onto [Cortana] search box, look for system model and BIOS Version / Date. Please post back information. In the meantime, change setting to Standard - see image below), and then power off system. Remove all peripherals, AC adapter and then wait about 5 minutes. Replace adapter and power on system. Hopefully battery start charging until it get to 100%.
I have been standing on my left leg to make it work. Just Kidding. All is well at the moment. Windows takes time to sink in. Literally, I only did what you said, and it worked and then it did not work. So I repeated your solution and it has been working for a few days. Windblows can be moronic some time and you need to whip it into shape =:-)