§393.30 requires every storage battery on a CMV to be securely mounted, located so that it cannot be flooded by water entering the cab, and (where contained in a compartment) protected with a non-conductive ventilated cover. The most common practical reading: the battery must not move, must not arc against the box, and must be secured against ejection in an accident.
Severity weight
Severity weight 2 in the Vehicle Maintenance BASIC. Findings cluster around the same root causes — corroded hold-downs, missing fasteners, a cover that no longer latches.
How it gets cited
The two patterns: (1) the battery hold-down strap or J-bolt is missing, broken, or no longer tensioning the case — the battery rocks in the box when the truck moves; (2) the battery cover or compartment is loose, missing, or so corroded that the terminals are unprotected. A wiggle test by the inspector produces the cite in either case.
How to prevent it
- Check battery security on every pre-trip — physical hand pressure on the case, not just a visual.
- Replace hold-downs on the maintenance schedule, not when they break — corroded steel goes from tight to gone in a single freeze-thaw cycle.
- Keep battery cover hardware in stock; the cover is often missing because the prior driver didn't put it back.
How Roadworthy HQ helps
DVIR pre-trip checklists include the battery check, and any defect entered routes through the §396.9(d)(3) repair-certification workflow before the vehicle returns to service.