Do any of you leave your cool box on overnight? It’s not a factory fitted one but one from a camping shop. It runs off 12v socket in my MAN just wondered if it was advisable to leave it overnight? Cheers
only done it by accident. battery was flat as [zb].
Really? I didn’t think they’d use a great deal of power! I’ve got home and paranoid as cant remember unplugging it!
xfmatt:
Really? I didn’t think they’d use a great deal of power! I’ve got home and paranoid as cant remember unplugging it!
take your jump leads with you tomorrow. 
limeyphil:
xfmatt:
Really? I didn’t think they’d use a great deal of power! I’ve got home and paranoid as cant remember unplugging it!take your jump leads with you tomorrow.
Yard is only 5 mins round the corner might go check quickly. Save me any hassle in morning.
They use about 40-50 watts which is almost as much as a car headlight.
Bloody hell im off to check it! Last thing I want is flat batteries in morning.
These things always really all depend on battery condition.
I’ve got a factory fitted fridge/freezer and the truck will still start after a week after putting new batteries in. Before, I changed them you couldn’t leave anything, like sidelights on all night and be confident of it starting the morning.
Best thing is to leave it on for 24 hours at a weekend and see if you can still start the truck then you know you’ve got a safety margin.
What I would do is maybe connect direct to one battery only to get the 12v supply, That way the other will still be good in the morning and you can get a quick jump and immediate start of any kindly passing car rather than needing another truck.
Luckily a lot of our trailers have got tail-lifts and the trailers have their own batteries so you can operate the tail-lift without a tractor unit hooked up. They trickle charge off solar panels on the roof.
No don’t leave it on if it’s a plug in unless it’s a compressor type or fitted by Manufacturer carry a set of jumpleads and learn how to jump start it in case you accidentally leave it on I can leave my fridge about 6 hrs but any long it’ll struggle to start and don’t forget to run the engine for 20 mins before you go to bed
i have got a 24v coolbox in one of my MAN’s, can leave it plugged in overnight no problems, but not over a weekend
i dont leave mine on overnight…have you felt the heat the 12v plug gets to during the day? it definitely will kill the batteries over a weekend, but should be ok overnight if decent batteries.
ive got a 12v cooler from halfords and it stays on all week and never affects the starting power in a morning. it does go off on a weeknd tho
jimmi:
ive got a 12v cooler from halfords and it stays on all week and never affects the starting power in a morning. it does go off on a weeknd tho
they chuck out some heat! and the noise!!! ARGHHHH id rather have tepid milk!
I have one of these in a van and they do heat up the plug an amazing amount. They’ll flatten a battery in no time. I only run it when the engine is on.
Always leave mine on overnight and never a problem.
I`ve got a Waeco Tropicool 35, leave it on with no probs, I think the problem lies with the cheaper models, they seem to draw more power.
Connecting any 12 volt appliance directly to one of pair of batteries is a bad idea, this battery will not get fully recharged by the altanator.
Also be carefull what you keep and eat from a cool box as most just reduce ambiant temp by x amount. So if x is 15 and ambiant is 25 your chicken is being stored at 10 deg!
Well i had the large halfords one and use to plug it in monday morning and unplug it friday night never a problem. I now have a mains/battery and gas one run it through my inverter and that stays all week and it never flatten the battery during the week. I did forget it one weekend and it flattened them but that was my fault
shuttlespanker:
i have got a 24v coolbox in one of my MAN’s, can leave it plugged in overnight no problems, but not over a weekend
+1
bazstan009:
Connecting any 12 volt appliance directly to one of pair of batteries is a bad idea, this battery will not get fully recharged by the altanator.
Only really a big issue if the one battery feeding 12v off is always drained near flat and the other never is. I’d view batteries as a consumable, really if nighting out they really want replacing ever couple of years anyway so I never think it’s worth trying to coax too much extra life out of them. A new battery fitted in the workshop won’t cost a lot (if any) more than a callout to jumpstart.