Why is Laptop Slow on Battery

Hello,

We have 2 exactly the same PC's that we use.

The mo del is Dell  Inspiron Gaming G7-W56701527033PTHW10 - the s ame for both PC.

VMPC4 (the name we give this PC) works exactly the same whether it is on Power or Battery.

VMPC3 (the other PC) works perfectly when on Power, but when on battery, it runs at least 40% slower.

 

The windows for both PC's is the same

VMPC4 =

 

VMPC3 = 

I can confirm that I have these settings exactly the same on both PC's

Can you advise me on what I can do to get VMPC3 working well when operating from battery?

Is there a setting I am missing?

 

Thank you.