46 C.F.R. § 129.353 Battery categories.
Title 46 - Shipping
This section applies to batteries installed to meet the requirements of §129.310(a) for secondary sources of power to vital loads. (a) Large. A large battery-installation is one connected to a battery charger having an output of more than 2 kW, computed from the highest possible charging current and rated voltage of the battery installed. (b) Small. A small battery-installation is one connected to a battery charger having an output of 2 kW or less, computed from the highest possible charging current and rated voltage of the battery installed.
Title 46: Shipping
PART 129—ELECTRICAL INSTALLATIONS
Subpart C—Power Sources and Distribution Systems
§ 129.353 Battery categories.