Decreasing battery charge / recalibrate


Ever since I bought the laptop, it has only been powered by a power supply. It’s not even 1 year old, but the full charge is only 68% now!
How can I recalibrate or what is the solution to reach 100% charge?
Anyway, my machine is perfect, I am completely satisfied with it.
Interestingly, even the latest Adobe programs run on it.

I use to calibrate my laptop battery.