Depends on what you are racing.

In my 1c carpet oval car, the difference between 4.20v and 4.22v is about 0.2 second - per lap - in my car. When you run lap times in the low four second range in a horsepower limited class in a car that's hooked up to the point where you are full punch from tone to tone, everything matters.

In my SC truck, I could likely not charge the battery for two rounds and degrade my lap times. Might be harder to jump the triple.