Slightly off topic .... Not sure I understand your question. One is coding that way to make the program as strong playing as possible. Users like to compare different chess programs, by letting them play vs. each other. A program using 100% CPU will be able to analyze more positions in the same amount of time, than a program using CPU moderately at say 5% and will in general be able to find better moves. (vs. most humans, it will not make any difference, and they will be rather chanceless. Still club players like to have their own human vs. human games analyzed by the strongest chess programs - world champions included)
Well, hardly any battery will last long under these conditions. I have a Dell Vitro i7. In the last 1.5 years it was running about half of the time at almost 100% CPU on all 8 logical cores. Of course it is connected to external power, and the fan is running all the time at max speed. When I see CPU dropping under 90%, I know, that I can strengthen the program, by optimizing the algorithm to analyze more chess positions in those unused CPU cycles...