Dell Latitude re-calibration problem

I have a Latitude 5411 laptop that is about 3 years old. It's battery drains fast, in about 1-1.5 hours after a full charge, mostly on web browsing and watching youtube videos. When I restart the laptop without recharging, I get prompted by the BIOS that the battery is low and whether to continue booting. I select to continue booting and the OS comes up. And then, despite Windows telling me that only 4 minutes of battery life is left, I end up getting another 1-1.5 hours of battery life. So it's almost like the battery is not calibrated correctly, that it's zero should really be 30% (or some higher number) battery life.
I have tried using the recalibration sequence (charge fully, then discharge on battery till it shuts down, even going on reboot and run on low charge till it finally shuts down and is not willing to boot any more) but that has not done the calibration.

Any thoughts on what could be going on and whether there is some other way of recalibrating the battery?
This is what the powercfg /batteryreport gives:

Installed batteries

Even though battery life shows only 18453 mWh in this table, in the last 3-4 days the battery at 100% charge capacity has shown between 18453 and 24670 mWh.

Any help in restoring battery charge capacity is much appreciated.