The Permalogic Selector System, designed by Phillips Industries for refrigerated trailers, pulls power from truck batteries or from the refrigeration unit to make sure liftgate batteries remain charged and the liftgate operating throughout a route.

Phillips’ Permalogic system is integrated into a sealed junction box at the nose of the trailer, and using a dual pole socket, senses which power source – the truck battery or the refrigeration unit – is most ideal for charging the liftgate batteries, according to the company. It will direct the charge to a DC to DC converter, boosting the voltage to 14.4 volts to accelerate the charge between deliveries.

Because it can pull power from the refrigeration as well, Phillips said, the liftgate will remain powered even when the trailer is not connected to a tractor.