Code of Federal Regulations Title 46. Shipping § 46.111.15–10 Ventilation

(a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent accumulation of flammable gas.

(b) Power ventilation. If power ventilation is required, the following must be met:

(c) Large battery installations. Each battery room for large battery installations must have a power exhaust ventilation system and have openings for intake air near the floor that allow the passage of the quantity of air that must be expelled. The quantity of the air expelled must be at least:

q=3.89(i) (n).

where:  q=quantity of expelled air in cubic feet per hour.

i=Maximum charging current during gas formation, or one-fourth of the maximum obtainable charging current of the charging facility, whichever is greater.

n=Number of cells.

(d) Moderate and small battery installations. Each battery room or battery locker for moderate or small battery installations must have louvers near the bottom of the room or locker for air, and must be ventilated by:

(e) Deck boxes. Except for a deck box for a small battery installation, each deck box must have a duct from the top of the box to at least 4 ft. (1.2 m) above the box ending in a gooseneck or mushroom head that prevents entrance of water. Holes for air must be on at least two parallel sides of each box.

(f) Weathertight. Each deck box must be weathertight.

(g) Boxes for small battery installations. Each box for a small battery installation must have openings near the top to allow escape of gas. If the installation is in a non-environmentally-controlled location, the installation must prevent the ingress of water.