Yes, I believe you are correct.
Intel has a similar technology called speed-step which controls the processor speed depending on load or if on battery power or A/C power.
Look at your power options setting and see if you can change how the processor acts on battery power.
There may also be a setting in the BIOS.
My old Dell Latitude C610 had a BIOS setting where I could set the processor to run at full speed when on battery power.