Parasitic Draw on RV?

Excellent responses here guys!

The good news is the solar kit I bought is easily scalable to 400 watts without any other modifications, so adding a panel (or three) shouldn't be terrible.

As far as losing food, you hit the nail on the head. We had what my wife and I estimate to be about $100 worth of food that we lost. To add insult to injury, the cost of an additional 100W panel is around $100.

This is a fifth wheel so no dash radio, no ecu's or anything like that. I guess I also don't know why it being an 04 means it has an inverter - ours doesn't. Between our family, none of the three campers have an inverter, and one is a 2015 model.

Or as an alternative, maybe remove the food and turn the refrigerator OFF if you're going to gone for a week?

Weren't there a bunch of RV fires caused by malfunctioning fridges a while ago?

Don't know the OP's situation, but with the RV two hours from home, when we left the RV there and went home for a few days, the RV fridge got emptied and we took the food home. Save a lot of trouble by taking a little trouble.

Those numbers sound pretty close to me.

A 100 watt probably isn't enough. That's only 7.7 amp in full sun, no clouds, no shade, clean solar panel surface, at the right angle, only at certain times per day. That will not likely do much other than add a couple days before your batteries go dead. I'm not sure how bad off your AGM batteries are now that they've been totally exhausted, I know that really shortens the life of a flooded cell battery set...but you might need to replace them.

500 Watts of solar panel would be better. 'Course that's a bit expensive. But that wattage would probably give you the kind of service you're looking for.

One thing you can do is only supply power to the refer by removing the positive leads from both battery sets while you're gone. In that case, you'd need to run a single wire up to the refer (16 ga) from the strongest battery set. You could also add a 2 X 1 battery isolator connected so both sets of batteries are supplying the refer (and ONLY the refer). Remove the +12 volt wire at the refer's 12 volt connector and substitute yours. Of course you could add a switch to toggle between the 2 sources.

So what would happen is that before you leave the lake is disconnect the battery positive cables, add your own going to the small battery isolator, run the 16 ga wire up to the refer (I'd just run it out the bottom of the battery compartment and up the wall of the RV to the outside refer vent). Connect it in place of the RVs 12 volt wire, and off you go.

And of course, do what you can to reduce the work the refer has to do. Park the RV in shade, or at least have the refer side of the RV in shade. Remember that the 12 volt will be running the relatively high current propane solenoid and circuitry, so the less often cooling is called for the better. So to reduce that run time, make sure the refer and freezer are free of frost, maybe add a battery operated fan to the inside of the refer to help cooling, don't over fill the refer or freezer, and make sure the outside vent is clear and open.

Some of those parasitic (vampire) loads are the CO & Propane detectors, the dash radio and other dash devices, the step circuitry, the transmission and engine memories in their respective ECMs, and the big one for a '04 I think would be a permanently wired inverter. Even if you eliminate those things, it always seems there's still going to be something else. And flipping off the saleman's switch doesn't always stop the vampire loads.

Have fun at the lake!

Feeding a battery is like having water to fight a fire

Either you have enough or you don't. No gray area. I would go with a 100 watt panel.

leaving the fridge on is NOT storage mode
there is no solar at night
in the 5 hrs of mid-day peak solar you have to replace every ampHr removed from the batteries during the 19hrs of low solar & no solar

also what happens if you have (2) cloudy or rainy days
your down 30ampHrs or more
how much overhead will you have to recharge the battery bank
i would prefer 200 watts of Solar

i assume the fridge has food in it
easy to have a $100 worth of spoiled stinky food in the fridge
when the batteries are dead
you've already experienced this once, don't go short on the solar

We don't know if your batteries died on the 5th day or the 14th day.

Given the 37ah/day, no, 100w would be short. The maximum output of that panel is 7 amps, only for a short time, and that doesn't include cloudy days. I'd go 200.

Your parasitic drain is not less than 15AH per day. 210AHs/14days = 15+AH/day.

A 100W solar system would be plenty for storage. No use getting anything smaller as the 100W panels are priced right.


HTH:
John

This dude measured 51AH down in three days leaving everything off except the fridge on gas.

The fridge draws 0.5amps when the burner is lit, and the whole trailer pulls 0.3a all the time besides, so with the burner , that makes 0.8amps the fridge cycles on and off all day--in my case it was on about 2/3 the time.

So in 24 hours, 2/3 of that is 16 hours at 0.8 = 12.8 AH, and
8 hours of 0.3 a is another 2.4 AH total =15.2AH so that cones out about right. I guess the fridge was on a little more than 2/3 the time to make it come out to 17AH per day.

So, how much solar will pull in 17AH per day? That depends on so many things. a 100w panel flat on the roof could do it easily on any nice day. What happens on not so nice days? Now you get in to the requirement to have enough battery bank to get you by until the sun comes out again.