UserAgent: Mozilla/5.0 (X11; CrOS x86_64 10176.68.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.144 Safari/537.36
Platform: 10176.68.0 (Official Build) stable-channel gnawty

Steps to reproduce the problem:
1. charge the Chromebook to 100%
2. keep working on it while on AC
3. after a while see the power indicator showing a charge value significantly lower than 100%

What is the expected behavior?

What went wrong?
The battery on my Chromebook is acting weird. Please take a look at the powerd log attached. 
You can see that on AC it apparently charged up to 3.766 Ah which is well above the charge_full_design value of 3.220 Ah as shown in power_supply_sysfs. Then, while still on AC, it suddenly dropped to 77% with charge of 2.888/3.766 Ah. Please note that I did not mess with the adapter or the power supply in any way, it just happened by itself. Then, when I turned off the power supply, switching to battery, the indicator jumped back from 77% to 100% with 3.006 Ah charge. In this state, when I run the battery_test the battery charge does not decrease - the test result says "Battery discharged 0.00% in 300 second(s).

Did this work before? N/A 

Chrome version: 64.0.3282.144  Channel: stable
OS Version: 10176.68.0
Flash Version: