When this happens, they are creating zero drag on your electrical system and in some small way may be helping reduce drag produced by other electrical systems. (mechanics.stackexchange.com)
In an area with erratic voltage, your surge protector might wear out in months or a few years; on other electrical systems, it might last indefinitely. (techhive.com)
By inhibiting surplus power generation, the multistage alternator control along with other electrical system efficiencies contributes to an improvement in fuel efficiency. (greencarcongress.com)