He’s lousy at math too.
Use 20% of battery capacity going up.
Gain 10% going back down.
“It consumes no energy at all!”
Actually you are the bad one at math:
“He reported reaching the top of the grade with 80 percent, then recovering battery charge to 88 percent on the way down”
That keeps happening, always in surplus.
How much energy is used to fill the dump truck?