waecos in a camper trailer

first of all get rid of the dodgy conections and run a heavy duty dedicated wire system to the fridges.
should help
cheers

Been learning this stuff myself recently - While the meter said you had 11.7 at the battery you would have had 10.4 at the fridge ! Lot of voltage drop in the cables and connections if not in ideal condition and spec. As mentioned, improve it all to the extent possible - heavier cable to the fridge and better connections - far as the fridges are concerned, they only want to know what the voltage is at their inlet point - and they need to be tested for voltage while running too ! If you have the pointy probes on the voltmeter, you can poke them into the pos - neg wires of the shielded cable to see what the voltage is - I found too much voltage drop in the original Waeco cable too - made my own up with heavier cable, and patched their plug onto the end of that - when the warranty runs out, I might wire MY heavier cable directly in through the case and onto the terminals inside.

11.7 volts is also almost dead flat (11.6 volts) so if the batteries are at this voltage, it doesn't matter what voltage (10.4 volts) the fridge auto cut out is set for.

OK, looks like I need to be a little more accurate.

at 11.58 the battery is down to 20% and generally this is as low as you should allow the battery to go, or you risk shortening its usable life.

So,

11.58 volts 20% 1.93 volts/cell
11.31 volts 10% 1.89 volts/cell
10.50 volts 0% 1.75 volts/cell

So, an auto cut out system that cuts out the fridge at 10.4 volts is totally useless. The battery is already "flat as a tack" and the device connected to it would have already ceased to operate. What the risk then is that the battery will "sulfate" causing even more of a problem.

Ozidave,

Here's a web site containing much information about batteries and it should provide you with most knowledge you should need.

Batteries - FAQ

Your battery is 11.7V with no load and as said, pretty much flat. Stick a load on it of around 5 amps and you will see it instantly drop to below 11V, this is why your fridge comes on for a second then cuts out as the voltage quickly drops to below 10.4V due to the startup current drawn by the compressor.

How do you find the fridges run inside the trailer, does it get too hot? I tried experimenting with running a 3way inside my trakshak on 12V but with the tailgate closed it just got way too hot, the compressor fridge will be a lot better I imagine but they still pump out hot air and your trailer is pretty much air tight.

I am playing around with planning for AGM's and fridges in either the trailer or back of the Prado as well. I found Collyn Rivers site very helpful especially his articles concerning all forms of vehicle electrics etc.

Do a search for caravansandmotorhomes dot com dot au.... I think thats it.

Cheers....Taz