All the battery data in the Battery report is retrieved from the Windows Management Instrumentation (WMI)

You can query the WMI directly using a PowerShell cmdlet. From a command prompt use...
powershell gwmi win32_battery
...more on that here:

What I have a problem with is that ever since I did a Bios upgrade WMI is convinced the Design Capacity of my battery is about a tenth of its true design capacity. I haven't yet found a way to reset WMI except the nuclear option...

If you suspect WMI or repository corruption, rebuilding repository is the last thing you should do. Deleting and rebuilding the repository can cause damage to the system or to installed applications. I guess I'm going to have to live with it. All the estimates of battery charge and remaining time are still accurate. Even the pretty graphs in the Battery Report look right. Its just that since October it's been saying...

Battery capacity history
Charge capacity history of the system's batteries
2016-10-04 - 2016-10-11 40,734 mWh 41,955 mWh
2016-10-11 - 2016-10-18 4,236 mWh 4,400 mWh
2016-10-18 - 2016-10-25 4,105 mWh 4,287 mWh