This app was mentioned in 7 comments, with an average of 1.14 upvotes
I got my GPDxd back on Jan15th and its already having this issue as well. Like others have stated, charge the device while its on and the screen is on. From what ive found online, you might also want to try this:
https://play.google.com/store/apps/details?id=com.blogspot.superthomaslab.batterycalibration
It supposedly rewrites the battery file. >This app does it by removing the BATTERYSTATS.BIN file. The OS then generates a new and clean BATTERYSTATS.BIN, so any invalid information (from the previous ROM) is removed. It is suggested, but not needed, to let the phone fully discharge, calibrate and the let your phone charge to 100% without interruption.
I've let my battery fully depleted and recharge to 100% then run the app. My battery still looses a bit of life while in sleep mode though.
https://play.google.com/store/apps/details?id=com.blogspot.superthomaslab.batterycalibration
I normally use something like that. Or the battery calibration tool from ROM toolbox. Depleting the battery is not mandatory in these calibrations
Something like this https://play.google.com/store/apps/details?id=com.blogspot.superthomaslab.batterycalibration will fix it. If it doesn't, you have a hardware problem.
I'm not joking. Battery calibration is a real thing, and if you don't believe me Google it or check out this XDA thread: https://forum.xda-developers.com/android/general/guide-how-to-callibrate-battery-device-t3308554/amp/
People usually do it after installing custom ROMs. Btw, there are a few fake battery calibration apps out there. I personally use this as I have root: https://play.google.com/store/apps/details?id=com.blogspot.superthomaslab.batterycalibration
Honestly, in your case I don't think this will fix it, but it's worth a try.
Don't judge anyone if your not sure about something. Do your research first. Just because something sounds silly doesn't mean it's not true :)
Hmm odd, are you rooted if so try this battery recalibration app https://play.google.com/store/apps/details?id=com.blogspot.superthomaslab.batterycalibration