Stop/Start

Many cars and 4x4`s are now built with a stop/start engine management including Volkswagen Blue Motion Vehicles. For anyone wondering - it is mean`t to save fuel by stopping the engine automatically in traffic, at traffic lights etc and restart as soon as the clutch or accelerator is pressed. The question is, is it wise to use it when towing due to the stop/start power supply to the caravan and has anyone suffered ill effects from using it.