I have an Acer Aspire ES1-511 and it's plugged in but not charging.

Had the same issue on my Aspire ES1-711 and tried every possible solution suggested around the web. Draining, recharging, and recalibrating the battery worked for me. Detailed method here: 

https://forums.tomsguide.com/threads/solution-laptop-plugged-in-not-charging-in-windows-7-8-10.460627/

Or here:

ALTERNATE SOLUTION - battery needs to be fully drained, then recharged, and thus recalibrated to the operating system.

I had this same issue on my Acer Aspire ES1-711 laptop with "non-removable battery" - system reported battery at "0% plugged in, not charging". However this proved to be a software/operating system issue and the battery was fine (I was still able to boot and operate Windows 8 with my AC adapter disconnected).

I tried every solution recommended on various forums from Acer to HP to Dell - most of which focused around uninstalling the "Microsoft ACPI-Compliant Control Method Battery" driver, disconnecting the battery, discharging residual power, rebooting, etc. My laptop's battery is "non-removable" so I even removed the bottom of the laptop case to inspect the battery and attempt solutions requiring battery removal (cable disconnect, rather than using the pinhole button on this laptop model). NONE OF THE COMMON SOLUTIONS WORKED FOR ME, though it's possible they played a role in part since I did attempt them first. I'll add a note about that at the end. 

WHAT WORKED FOR ME:
- change power settings in Control Panel to not shutdown/sleep/hibernate on battery power, then set critical battery power shutdown to 5% so battery can nearly fully drain.
- [OPTIONAL 2nd STEP] This might be the time to uninstall the Microsoft ACPI-Compliant Control Method Battery Driver in Device Manager - DO NOT SCAN FOR HARDWARE CHANGES AFTER DRIVER UNINSTALL COMPLETES
- disconnect AC adapter - Windows might shutdown/sleep/hibernate immediately if it thinks your battery is low/critical, if so leave AC adapter disconnected then reboot and run on remaining battery power (even if meter reports 0% as mine did). If Windows did shutdown/sleep and you had to reboot, the Microsoft ACPI-Compliant Control Method Battery Driver may reinstall itself upon reboot. Check Device Manager to confirm it is still uninstalled or uninstall again if necessary. 
- let battery discharge to 5% and Windows shutdown automatically. I recommend leaving it shutdown and disconnected from the AC adapter for an additional hour. 
- reconnect the AC adapter and allow the battery to charge with the laptop still powered OFF for about 2 hours or until mostly charged. 
- [SECONDARY ISSUE] At this point I actually booted to a BSOD with error code 0xc000021a and had to resolve that issue separately before I could boot to Windows normally to check on the battery issue. If you have this issue as well, my solution was to tap F8 at boot to get to the Start-up Recovery Menu, booted in Safe Mode, ran Command Prompt and scheduled Chkdsk c: /r for next boot, then rebooted. After chkdsk completed I was able to boot to Windows 8 normally.
- Boot to Windows normally and the battery should now be charging and reading correctly in the system tray. 

As I mentioned, I had tried a variety of commonly suggested solutions before draining/charging/recalibrating my battery seemed to be the correct solution. Consider adding parts of those solutions to your method as well if you still have issues and are certain both your battery and AC adapter are not defective.