After some help
Have a 59 plate stralis and the sockets switch off after about 10mins at night (I need a breathing machine at night not ideal). Is there a way around this? If I keep the interior light on or get up and press the battery switch they stay on but most be something you can do!! thanks
Yeah this is what the Stralis does. Try pressing the battery button as soon as you stop. Should stay on for longer. However in the one that I drive I do get the sockets on for about 1 hr before they turn off. Its a way for the truck to not get a flat battery so I think the battery button switches to the secondary battery, but I could be wrong on this.
Ok will give that a go cheers. Best option is to leave the internal red lights on and wait for a knock at the door asking how much 
Leave the ignition on the first position. I’m sure that stops the isolator kicking in.
Not on mine it dont!
t’is a pain in the 'arris !
They are an absolute nightmare! When we get a few of us parked up together, we are sat chatting and the isolator is forever kicking in plunging us into darkness!!!
Have you thought of getting a car battery booster(jump starter) with a power socket on it and using that for your breathing machine? I would think that would do for a while. Maybe you could charge it up during the day using an inverter.
Can you not have a chat with your boss and ask for a permanent feed direct from the battery to be wired up for your machine. It’s a fifteen minute job and would solve your issue.
Pwyll:
Can you not have a chat with your boss and ask for a permanent feed direct from the battery to be wired up for your machine. It’s a fifteen minute job and would solve your issue.
The boss did say he would do that if no other option, thanks for your help
damoq:
Leave the ignition on the first position. I’m sure that stops the isolator kicking in.
^This should work.
Alternatively less hassle than running a feed may be disabling the isolator solenoid it’s mounted next to the battery box. Obviously the batteries will stay connected but unless they’re knackered or there’s an excessive drain it should be ok. There are products that will make an audible warning when the batteries are getting low that could be worth fitting.