This screen shot is from experimental 0C 3774 (windows graphical), but I was able to re-produce a similar effect in 3798 as well.
In 3798 it seems to max out the battery power rather than going to 1.2MM.
Simply add a scoop to an electric vehicle and scoop something up to see this effect. Bonus round, farm, you’ll see how the power can jump all around from 1.2MM to negative %s as well as you suck up all the veggies.