Hi All can anyone tell me what size of solar panal I would need to run a Halfords cooler box and can it be done The box runs on 12v as well as 240, when I put it on 12 volt it runs great but as I have only one leisure batt it runs the batt down I can start the van and let it tick over and again the box runs well but I don't want to keep running the van every few hours or so any info would be great