i worked for a firm that pulled us for excessive idling…they soon learned when they got a call ( at home in bed ) at 0400 to say the batteries were dead, and cost them £350 for a jump start ( in a layby ) as i explained…i had to recharge my batteries as during the evening i run my Fridge, Heater ( winter time ) kettle, phone charging, and of course my dvd/tv…prior to my bollockings, i use to run the engine…then they told us not to, i think that week it cost them over £2000 in recovery fees…they left us alone after that…they finally got the message as to who knows best.