running a laptop you are better getting a 12volt charger off Amazon - better than an invertor
As already posted your batteries are knackered - but just check the acid levels - sometimes they are not covering the plates and it can cause this problem
cheers
Steve
xamtex:
you can get jump leads with an anti surge device fitted…we had to get a set years back after toasting the gaffers bmw ecu!..takes out the voltage spikes that damage ecus and the like.
They are useless as the surge doesn’t go through the leads it comes from the vehicles alternator.
Coffeeholic:
cliffton 27:
Plambert:
cliffton 27:
u mean change batterys in waggon its an 11 plate scanny should not need changing yet shurleyEven Scania batteries fail
spoke to a mate of mine he says change the lead on the cool box for a 12v and when finished with inverter run the engine for 5 mins after and should be okThat advice is pretty much guaranteed to increase your battery problems. Running the cool box on 12v instead of 24v will double the current it is drawing and you will take more out of the batteries starting the truck than 5 minutes running will put back in.
The laptop will draw less if you have it fully charged then use the inverter to run it, keeping at full charge, rather than letting it go flat then charging it back up.
Also, is it the 1000w inverter from the other thread you are talking about? If you have got a 1000w inverter for running your laptop that is overkill, a 24v 150w inverter will be more than enough for that and far kinder to the batteries.
yes it is the same inverter im gonna run a microwave off it too thats why i bought a 1000w i would have never bothered with a big watt one if it was just for the laptop thanks for the advice mate
well thanks for all the input guys i think it may be down to duff batterys but its not my waggon and im gettin mine back next week so fingers crossed it wont happen again
I had flat batteries on a brand new Volvo a few years back.just after N reg came out so it would be about 1995.
I had picked up the truck, then loaded and run to Immingham for the Gothenburg ferry
Was parked in Stockholm overnight and only used the interior light to read a book for about an hour…next morning flat as a pancake, this was in the summer too so weather wasnt a factor.
Rang up Volvo Action Service who arrived within 30 mins with a SCANIA 
wrecker, jump started it and followed them to the workshops.
Turned out to be a faulty voltage regulator. Could this be the problem on a 11 plate ■■
cliffton 27:
u mean change batterys in waggon its an 11 plate scanny should not need changing yet shurley
just cos its an 11 plate doesn’t mean it hasn’t sat in a compound for a couple of years first.
both good points i just thought with it being a new truck the bats were not an obvious thing really stupid i know 
Just out of curiosity how much would a couple of new batteries cost?
£600
cliffton 27:
i woke up this morning with and waggon was dead the only thing i can think that caused this was leaving the coolbox on overnight i have done it before with no problem but i just got this one and it has a 24v hella plug on it if i change it for a 12v lead will i be able to run it through the night and not kill the batterys
the only other thing i can think that i had on that night was my 12v inverter and that was only for 2 hrs max while i charged the laptop
Your Lorry shall have a Relais which switches Fridge,Webasto,ect,ect off when Power falls down to 22volt.
Means,one of your Battery failed.