First of all apologies if this is in the wrong section 
I’ve been given a different truck for a while,volvo. I have a 9v portable tv but in this wagon there seems to be no power to the cig lighters unless the ignition in on. No aux power on the key. Pretty daft and basic question but to watch the tv I need to sit here with the ignition on unless I want the engine running put as I’m parked up with a few other wagons,most of which look to be asleep,having the engine running wouldn’t be the most considerate thing to do! So I’m wondering if it will drain my batteries fast havin the ignition on to watch the tv? I’m one of these paranoid people who dreads turning the key in the morning and having no power!!
Thanks in advance
I remember the days when trucks were for working in and the sette at home was for watching telly. 
If your batteries are in good order 3 or 4 hours tv no problem, ignition on should be ok, think i had to do that with an old merc.
Can you not get power with the key turned to the first position? in other-words, turn the key until the radio lights up. As far as im aware you wont get power in any truck or car without the key being turned to this position. (I may be wrong!)
As for batteries, the Volvo batteries are bad, they must install the cheapest of the cheap in new trucks, my truck is 1 year old (Globetrotter) and im on my second set of batteries, at first we thought they were faulty but then a couple of the other newer trucks had the same probs.
If you have a fridge in truck, have a look at the light on the front every so often, it should be green. As a safety measure when the battery power is low the fridge is the first thing to stop working and the light will go red, I normally start the engine and run for 20 mins and this gives me a few more hours. Hope this helps/