Got a new gamic trailer ordered with the electric lifting deck. I understand that it comes with a cable to fit under the pickup and straight onto the battery which is fine. However there may be the odd time we will want to use it on the back of our discovery 5, as I don’t want to run a cable under such a complex vehicle in case it upsets the vehicle electrics what is the best option for powering the deck assuming the 12v plug in the boot is only 120watts and is not man enough. TIA.