255% available (plugged in)

Open your laptop and re-connect the battery connector. Put a piece of insulation tape on top to ensure it remains seated without any loose contact. 

It should resolve your issue.

Good luck.

I'm also experiencing the same issue all of a sudden. At first I surprisingly found my laptop drained out even though i had it charged before and when i turned on it showed 0% available and not charging and on startup it showed there's a battery issue. On uninstalling the drivers, my laptop turned off. I restarted it and updated my Windows and on restart this problem emerged where it's showing 255% available but this time it's still working without the AC support. On removing AC support it shows Unknown remaining

I am experiencing this too! @nikhilkhadgi, do you recommend to Disable, or to Uninstall Microsoft ACPI-Compliant Control Method Battery? I wonder which works better? 

Thanks for your help! 

I have the same problem in my ASUS GL553VD laptop. 255% available is shown when you scroll over the battery icon. Sometimes the battery is detected sometimes its not. Also, the battery indicator constantly keeps on blinking like the laptop is about to run out of battery. I have already purchased two replacement batteries which did not solve this problem. Even tried replacing the charger but the issue remains.  

One thing that I have noticed is that when you unplug the AC adaptor, the laptop turns off immediately. But when you disable or uninstall Microsoft ACPI-Compliant Control Method Battery from device manager the laptop does not turn off. In fact it lasts until the battery is drained out completely. I have no idea whether it is a hardware issue or software issue.

I think this happens when the internal battery is totally drained or is  not functioning or not present. I have replaced my battery and my problem is resolved.

How do you replace the battery in Microsoft Surface Pro 4?

Did you take your battery out? 

How do I take the battery out in a Microsoft Surface Pro 4?