30 CFR § 7.45
The following critical characteristics shall be inspected or tested on each
battery assembly to which an approval marking is affixed:
(a) Thickness of covers and boxes.
(b) Application and resistance of insulating material.
(c) Size and location of ventilation openings.
(d) Method of cell terminations.
(e) Strain relief devices for cables leaving boxes.
(f) Type, location, and physical protection of cables.