I tried reviving an old thread and was told it was too old.
I just got back from a short solo weekend of dry camping. I ran the furnace for about 20 minutes at most. The lights were used infrequently, and the water pump switch we left on, but not used for extended periods. The refrigerator was on the whole time. At the end of 36 hours, there was very little battery power left on a system using two deep cycle batteries. I have a 2016 Roo 21BD. I did accidentally leave the amber porch light on over night last night. I still would not expect there to be that much battery drain by myself. The refrigerator I have is a Dometic model DMR702. I can't find in the owners manual that it has the defrost element that people are referring to with their older models. It has what they refer to as a heater, but make it sound like it is the heater for the cooling system to even operate. The sticker in the door says 2.7 amp when on 120V, but nothing when connected to 12V. Any ideas?
Finally, will a 200 amp solar panel be adequate to keep the battery boosted enough to extend the dry camping trip without necessarily fully charging the batteries in a day. I know most people I see are saying 400-500 amp. We rarely go for more than 3 days and only need to be able to prevent totally draining the batteries.
I got by fine on two group 24 12Vs for two or three days without dropping below 60% charge. You shouldn't need solar for what you're describing. Leaving that outside light on MAY have dropped it a good bit. How are you checking charge and how are you charging?
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2015 Chevy Silverado LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition
I charged with shore power for more than 24 hours prior to leaving. I am checking with the lights on the panel just inside the entry door. It showed all four lights being on when I left and this morning it was at the 1/3 light. I haven't done anything more scientific than that at the moment. We felt like we were having trouble last fall after we got it because we were constantly needing to monitor battery usage every time we went out. We feel like there is something that is draining the batteries that we are not aware of. Purchased the second battery at the dealer when we took delivery in order to make sure that there would not be a problem. Last fall we went out and it was cold enough that we needed to run the furnace the first night. It killed the batteries that night.
I'm starting to question the health of the batteries. The deeper you discharge them and the longer you go before fully recharging can shorten life on them. You've most likely got hybrid / marine type batteries that aren't really ideal for deep cycle use. They'll work, but you've got to take care of them. It's also possible you've just got a weak battery. The status lights are a joke, but 1/3 will generally tell you that you are actually on the low side. It sounds like you use your rig like I use mine. What I ended up doing after my 12V finally died (took about four years) is switch to 2 6V in series and get a good charger ( I use a CTEK 7 stage ) and just leave it plugged in when not in use.
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2015 Chevy Silverado LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition
It's still possible that one of them isn't holding a charge and dragging the other down with it. Your two big battery killers are going to be water pump and furnace. Water pump shouldn't be an issue unless you use it a lot. Your refrigerator controls and CO detector will constantly pull, but it's fairly minimal. I'd pull them and have them load tested (on a deep cycle test) just to see, it may not show anything but if it does, you'll know for sure. I had this exact thing happen to me this past fall. I went to kick on the furnace and the lights dimmed on night number one. One of my batteries died. They showed fully charged when I left the house 12 hrs earlier and the only thing running was the refrigerator control and the CO detector.
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2015 Chevy Silverado LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition
they were both brand new. Do you know if the option I have seen to cut the wire on the heating element works on this fridge?
It works but have not done it yet, the wire can be found through the light switch access hole.
Here's your fridge wiring diagram.
T is the heating cable being referred to as the defrosting circuit.
Thanks for all the info. I am going to start doing some testing to find out if there is a hidden draw that I am not aware of. I will also do a load test on the batteries. Never know, but at least it could save or create more work depending on the results. I will probably disconnect the heater cable regardless. Since it isn't used for extended periods and then turned off, I can't see condensation being an issue. Again, thank you for the info.
I think you have a typo in your initial post. I assume you are asking about a 200W solar panel. A 200amp solar panel set up would be much larger than your RV. Try changing some lights out for LEDs if not already equipped. Disconnect the Fridge door frame heater.
Kinda of a useless recommendation for a hybrid TT owner, since there's only room for two batteries on the tongue.
If you can handle the taller 6v golf cart batteries, you should consider them.
I couldn't because of clearance issues with the electric tongue jack.
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Dan-Retired California Firefighter/EMT
Shawn-Musician/Entrepreneur/Wine Expert
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
4pt Equal-i-zer WDH and 1828lbs of payload capacity
I'm starting to question the health of the batteries. The deeper you discharge them and the longer you go before fully recharging can shorten life on them. You've most likely got hybrid / marine type batteries that aren't really ideal for deep cycle use. They'll work, but you've got to take care of them. It's also possible you've just got a weak battery. The status lights are a joke, but 1/3 will generally tell you that you are actually on the low side. It sounds like you use your rig like I use mine. What I ended up doing after my 12V finally died (took about four years) is switch to 2 6V in series and get a good charger ( I use a CTEK 7 stage ) and just leave it plugged in when not in use.
The "1/3" light is actually an "F" - "fair" when you read the battery; it only means 1/3 when reading tank levels. In this case it means your 12 volt battery is outputting more than 11.6 volts. (near death).
My guess is you have exceeded the number of usable cycles due to discharging your battery below 50% capacity too many times ("G" light JUST goes out - or the "2/3" light)
200 watts of solar won't help you if your batteries are toast.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
I appreciate all this information. I have charged my batteries and given them 24 hours rest to determine whether they are even holding a full charge. At this time (24 hrs later) they are both sitting at 13.00V. I guess I need to have a load test done to determine overall health. They haven't been used that many times, but I guess they could be toast. If I do need new batteries, then is a 200W solar panel enough to keep me up and running above the 50% with "normal" usage?
I have charged my batteries and given them 24 hours rest to determine whether they are even holding a full charge. At this time (24 hrs later) they are both sitting at 13.00V.
Can't be...13.00 is to high for a flooded lead acid battery. as far as the 200 watt solar installation...what is "normal use." Without a big inverter and residential reefer, 200 watts should be enough for lights and such. Remember its 200 watts on the best day, with the sun shining directly on the panel. I am using 300 watts for 6 batteries and a residential reefer, but I will use the generator to get a boost charge for 3 or 4 hours a day in addition to the solar.
I appreciate all this information. I have charged my batteries and given them 24 hours rest to determine whether they are even holding a full charge. At this time (24 hrs later) they are both sitting at 13.00V. I guess I need to have a load test done to determine overall health. They haven't been used that many times, but I guess they could be toast. If I do need new batteries, then is a 200W solar panel enough to keep me up and running above the 50% with "normal" usage?
There are many web sites with instructions on how to calculate the size solar panel you need based on battery bank size and your predicted usage.
There are just too many variables to predict how much solar you would need.
I can tell you that 200 watts is enough to power a TV for a few hours and that is it.
A 100AH battery contains (12 volts X 100 amps) 1200 watts for 1 hour till dead (Math here is theoretical since it is impossible to get 100 amps out of a battery for an hour due to the Peukert Effect - PE) or 5 amps at 12 volts for 20 hours (5A x 20H = 100AH) which is the rating and also equal 1200 watt/hour @ 12 volts.
As discharge rate goes above 5 amps, the PE reduces the AH the battery can deliver.
For example, from the graph, we need 10 amps to run our camper. Due to PE, the capacity at that load drops to 78AH. So at 10 amps, the battery will last 78AH/10A or only 7.8 hours.
Remember that Peukert Effect impacts charging too. You just can not smash 1200 watt hours into a battery without burning it up.
If you charge at 10 amps, it will also TAKE 7.8 hours to replace that charge (provided your solar charge controller will do that, which it won't due to the charge rate dropping as the battery fills, just like your dedicated charger or Converter does).
If you plan on more than that you will need a lot of battery and a way to recharge them every day beyond solar (which will cut down on generator time each day).
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
It works but have not done it yet, the wire can be found through the light switch access hole.
Here's your fridge wiring diagram.
T is the heating cable being referred to as the defrosting circuit.
Following, we need to run our fridge in the storage lot and turning of the ndoor defrost will certainly help with draw.
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B and B
2022 Venture RV SportTrek STT 302 VRB Travel Trailer
2018 Heartland Landmark 365 Louisville 5th Wheel
2015 Heartland Bighorn 5th Wheel
2013 FR Rockwood 8289WS 5th Wheel
2012 FR Rockwood 2703 SS Travel Trailer
Linear Mode
