My Jayco has a 100 AH on board deep cycle battery . If the misses and I stop for a brew while travelling will the caravan fridge draw power from the on board deep cycle or the car battery.
The heavy current draw of the fridge will come from the tugs battery (if it is not isolated when you switch off.) The radio, lights and anything that will run when you are unhitched and off power will run off the vans house battery.
It's important to have your fridge isolated from your tugs system when the motor is not running. Dometic recommend you do it this way.
My Jayco has a 100 AH on board deep cycle battery . If the misses and I stop for a brew while travelling will the caravan fridge draw power from the on board deep cycle or the car battery.
Regards
R and B
Well again I am going to disagree with most others because the answer depends on what type of 12V fridge you have (absorption or compressor) how the van fridge is wired up and how the van battery is wired up to the tug.
Most van fridges are NOT wired up to the tug, they are wired up to the van battery.
If so, if your tug is off the fridge continues to run from the van batteries. 3 way fridges suck down 10amps or more per hour but can be switched over to gas whilst stopped for a few hours or overnight free camping, something compressor fridges can't do, they need either 12V DC or 230V AC. Compressor fridges are much more frugal on 12V power compared to 3way but always need an electricity supply of some sort.
If you do not have some isolator system (relay or DC-DC charger) that separates the van batteries from the tug battery as the fridge runs down your van battery so too does it run down your tug battery, and you may well find yourself unable to start the tug after a nights camping with the fridge on 12V.
So, to definitively answer your question we need to know the type of fridge and how it and the van-to-tug is wired.
Hylife, what you have written is correct in my case, however I have a 12 volt fridge. It is a Jayco, a fairly new model. The wiring diagram they supply shows power coming off the 12 pin trailer plug on pins 8 & 9 to service brakes, and 12v accessories, fused at 20A, but then there is another pair of cables coming off pins 11 & 12, fused 30A and labelled fridge.
When I enquired about these to the Jayco agent, they told me they were connected to a three way fridge, and not used in my case.
Hylife, what you have written is correct in my case, however I have a 12 volt fridge. It is a Jayco, a fairly new model. The wiring diagram they supply shows power coming off the 12 pin trailer plug on pins 8 & 9 to service brakes, and 12v accessories, fused at 20A, but then there is another pair of cables coming off pins 11 & 12, fused 30A and labelled fridge. When I enquired about these to the Jayco agent, they told me they were connected to a three way fridge, and not used in my case.
Ah , so you do NOT have a 3 way fridge then, you have a 2 way compressor fridge. Compressor fridges can consume as little as 1 amp per hour for something like a modern 50 litre portable up to 3 or 4 amps per hour for a huge 190 litre inbuilt. When you are using such piddly little amounts of juice, the fridge will usually run quite fine from your tiny trailer plug wiring, but make sure the power continues once the tug ignition is turned off and that you have either a secondary battery or a voltage sensitive isolator connected to your cranking battery.
3 way fridges consume from 10 to 15amps and just can't get enough juice for the heating element from thin trailer plug wiring and usually require an Andersen plug and heavy duty (6 AWG = 13mm square) wiring from the tug to the fridge. 12 pin trailer plugs have an extra 5 oversized pins that can be used for heavy duty wiring, such as to a 3 way fridge. I personally still prefer the 50amp Andersen plug because it is generic and I can connect in so many devices that can either produce or consume large amounts of power. Things like portable solar to the tug aux batt or even to jump start another vehicle.
