This battery hold down bracket and rods are specific made for Precedent series, not for SB series. This bracket is so important that lots of owners or mechanics never pay attention to it. This bracket can hold the battery tight on the unit, to avoid the vibrating, or up and down when the trailer running on the uneven road, which will cause the battery cables or wires broken any time after times.

The significant signs for this, when battery is new, but reefer HMI says "low battery voltage with code 61 or code 25".