[Code of Federal Regulations] [Title 46, Volume 4] [Revised as of October 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR111.15-25] [Page 222] TITLE 46_SHIPPING (This book contains parts 90 to 139) CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 111_ELECTRIC SYSTEMS_GENERAL REQUIREMENTS--Table of Contents Subpart 111.15_Storage Batteries and Battery Chargers: Construction and Installation Sec. 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 rectifier 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.