Kindly follow the below mentioned Troubleshooting steps:
1. Disconnect all peripherals, remove the battery and confirm if system is working fine with AC Adapter or not?
2. Remove the battery and AC adapter/power cord from your Dell notebook, press and hold the power button for 20 seconds to discharge any residual current inside the laptop. This clears RAM and is like hardware reset. Restart your computer.
3. Check the AC Adapter and Battery status in the BIOS and Check Battery Health Meter.
5. Try swapping with a known good battery (If available). If known good battery works, Replace faulty battery.
Hope this helps
Thanks & Regards