Section 111.15-25 - Overload and reverse current protection(a) An overload protective device must be in each battery conductor, except conductors of engine cranking batteries and batteries with a nominal potential of 6 volts or less. For large storage battery installations, the overcurrent protective devices must be next to, but outside of, the battery room.(b) Except when a converter is used, the charging equipment for all batteries with a nominal voltage more than 20 percent of line voltage must protect automatically against reversal of current.CGD 74-125A, 47 FR 15236, Apr. 8, 1982, as amended by USCG-2020-0075, 88 FR 16361 , Mar. 16, 2023