isolation said:
Definitely aiming to go the dual set up, just wondering if it would run me flat overnight with just the main battery at the moment?
Check my thread on Bush Power
https://www.prospectingaustralia.com/forum/viewtopic.php?id=9156
But in short, as a guide my Engel uses about 1AH per hour on average in wintertime, at this time of the year, it would be more overnight and on one test I did it pulled 25AH during daytime over 8 hrs.
So if you stop the engine at say 4pm and don't restart till 8am the next day (16hrs), you can draw at this time of the year around 30AH min possibly more. My fridge is only a 30lt Engel, so a larger fridge and different brand can use much more. If your starter battery is a few years old, you might have a cold beer for breakfast, but you'll most likely be walking.....
Although I knew better, I had my fridge in the back of an AU2 wagon years ago, I had it running direct from the start battery of the car and forgot to connect it to the Thumper I carried as well. Four hours after getting to the caravan park (Flinders Ranges and a bloody hot day, my car alarm went off, lights flashing etc. I had to disconnect the battery to shut it all off and not only was the start battery flat, it was now totally buggered. Although I got a new battery from Leigh Creek, I paid a premium price for it. I also had no radio until I got home as the code was not in the car and the central locking was a pig to reset. The RAA mechanic was there for near 2 hours, just to get me going. The battery was a few years old.
Fortunately it didn't happen 2 days before, as I was bush camping and rarely saw a car, had no mobile signal and at that time no PLB
My Advice, keep the start battery for starting the car not to run a fridge.....