Cold weather dry camping battery draw

[AChaulk]

Can't find this answer on even my Grand Design Forum, so I'll try asking it here.

I have a 2016 Grand Design 303RLS 5th wheel that I tow behind my 2016 Ram 2500 TD. Truck/Camper combo works great. Big improvement over my 2001 Ram 2500 TD.

I'm going on an Alaska Trip next year. One time 'bucket list' kind'a deal. There will be an occasional night of pulling over to the side of the ALCAN highway and spending the night. The rest of the time we'll be at a campground with full hookups.

My 5th wheel has nothing special in the line of battery banks or generators...yet. Just the standard 12 volt deep cycle lead/acid battery that came with the rig.

All I'm trying to figure out is... If I pull over and shut down for one night... If I run my Dometic 35,000BTU heater with an interior temp of like 65F, a couple of LED lights and a few cycles of the water pump to flush the toilet, will I make it through the night without killing the RV battery??? (I'd probably pull the RV 7 pin plug from the truck to prevent drawing down the truck batteries.)

This will be in late May and Early June so I would assume that the outside temp will be in the 40s at night in the Yukon territory and not below freezing.

I'm also wondering if I do suck down the RV battery really fast, If I start up the truck, how many amps can the truck supply to the RV battery system through the 7 pin connector? I've heard there is a limit on the output to prevent the wiring from frying.

I know I have several options with either bringing a generator, getting two or four 6v batteries, solar, running the truck, etc. to survive the night but they all cost some bucks. But if I only do this for like two separate nights during the entire trip and never dry camp again, why spend a bunch of money on it.

Thanks!

 

[cbrown2015]

I don’t think you can run a any heater or cooling device off of a battery or twelve volt source. If you boondock, you will need a generator. Warm clothes and a sleeping bag is your easiest, cheapest, lightest bet.

 

[Dan_69GTX]

Temps could be below freezing - depending where you stop. Years ago we traveled to Alaska in June and there was still snow on the ground.

If you have a group 27 battery, that isn't sulfated, I can't see how you couldn't make it through the night. Depends on what other draws you have - such as the refrigerator. Not sure about a group 24, but that should work too. I've done this many times camping in the fall with cool weather. Then I got 2 6V batteries and can go a couple of nights. In the summer we run several fans all night long and one or 2 during the day.

If you are really concerned, do it now when it gets cold out - test it!

Oh yea - regarding charging. Even if you plug in, you are not charging at a very fast rate, so your truck will charge the batteries similar to your converter.

 

[bigceltic]

I would think you would be fine. I just dry camped for 4 days, 3 nights and ran my heater (set to 60 - got down to the high 30s at night) at night along with water pump and led interior lights and never went below 50% (that being said, I use 6V Golf Cart batteries and have a solar panel). I have done multiple day dry camping trips in the past with my pop up on a single 12v deep cycle and lasted 2-3 days running the heater at night. I assume your heater is propane and the battery will only run the fan. I can't see why you would not be fine for one night.

 

[Tuesdak]

Let me rephrase the question for you. 'I would like to know if the cheapest "garbage" dual purpose battery the dealer gave me will last the many nights being charged by a very small charge wire from my truck without a battery fuel gauge of any kind. The warranty on the battery is one year maybe 90 days.'

RV makers are setting you up for failure. Let's address the problems so you don't have to worry about the 12v system on the trailer during your trip.

First the battery is likely going to be weak when you take the trip from unintended abuse to where it won't hold a full charge anymore. It will die early having the fridge low volt alarm wake you up in the middle of the night with the heater INOP from low voltage dead battery. So new "real" Deep Cycle battery before you start the trip. Dual purpose cheap batteries are not good at either. Cheap and good would be a pair of Trojan T105 6v golf cart batteries wired for 12v. Expensive is AGM Lifeline.

How you going to charge the battery? Solar? Generator? Campground? (Truck is a special case.)

Campground and Generator both are hampered by the Trailer's converter. You need to make sure the converter is a 3 stage charging converter that raises the voltage to charge the battery as fast as possible. Otherwise not only is genset run time wasted, but, it may not completely charge up overnight in the campground. What model 120v to 12v converter is in the trailer now? Some have an optional $25 part to make them 3-4 stage charging. Standard converters assume RV park 100% of the time and charge slowly over days.

Solar needs good heavy wires to charge the battery as most installs skimp on wire size. Do you have solar? I'd buy solar before a generator.

Charging from the truck. Yeah right. Not gonna happen through stock wires. So the OEM long run of small gauge wire to the trailer through the truck is good for maybe topping off the batteries. The voltage drop on that small wire for any kind of current is so bad that no real charging takes place. You could overcome this with some heavy gauge wire and a jumper cable type of connector to the trailer to get some current and voltage to the trailer. Both positive and ground need thick wires to charge. If you don't get a genset for the trip I would recommend modifying the truck and trailer to have heavy gauge wire installed just to charge the trailer batteries while you drive.

Battery fuel gauge. How many amps did you take out of the battery, is it charged back up, what stage of charging is it in? Can I leave the campground now and have the truck finish the top off charge? You wouldn't drive the truck with a INOP fuel gauge. Other than cost being why OEM RV makes don't install more than a useless voltmeter why run the 12v system without an accurate gauge of what's left in the battery? I suggest a Bogart engineering TM-2030-RV to see how much you use out of and charge back into the batteries.

In depth here:

https://www.turbodieselregister.com/threads/rv-house-batteries-for-dry-camping.259757/

 

[Ozymandias]

Get a Generator, only way with your appliances and batterys.

 

[Road Dog]

JDoremire summed it up. I'm surprised a 5th that big has a single battery. With my slide-in camper I get 3-4 days from a fully charged single battery in the Winter (now I have 2). My furnace is half the size so it has smaller blower motor which draws less power. The furnace blower is the biggest draw but a modern fridge draws 1.5-2A 24 hours a day just for the controller. The hot water tank on propane is probably 1-2A as well although I can't find actual numbers.

If the battery is good (you can have it load tested) and fully charged I would do one night. Two would be pushing it.

 

[BarryG]

While I don't disagree with Jdoremire at all I can say that I have 1 12v dealer supplied battery in my 5er. I have used electricity sparingly like you are talking about and gotten through two consecutive nights without issue more than once with no driving/charging in between nights. Though your trailer is bigger than mine. However I have no problem leaving the heat off or as low as the thermostat will go and not turn it on until I go to bed if I do with lows in the high 20's to low 30's. If you are cooking dinner on your stove that will heat up the trailer or at least part of it as will a cup of hot tea or the like just before bed (I am not advocating heating your trailer with the stove burners at all but if i cook and it gets warmer I am not opening the windows and so be it). Did I sweat it each time yes but I got through ok. Will the truck charge up the batteries dang sure not quickly and perhaps not even a full charge after a full day of driving. Road dog mentions a couple of items that I did not use while doing my stays no hot water and no fridge. These were just spur of the moment early or late season weekend fishing trips in the mountains rig was winterized already or still winterized so I just took a cooler and took some water in a jug so I had no other energy suckers going aside from the gas alarm. Really just used it for sleeping and eating, put on a coat when required and listened to my ipod and or read under a single light until I went to bed.

 

[Northfork]

OP....
All we do is boondock; have for years. The truck will provide some charge during an idle but it is inefficient as heck...
Depending on where you set the thermostat and how cold it gets you might last a night with the factory supplied battery.
Couple of options...
Buy a pair of Trojan T105 6v Batteries. I would do this first. Couple hundred bucks for the pair.
If your rig has a space for a generator but didn't come with one watch for a sale on a Honda EU2000 inverter genny. You can find them for under $1000 on sale a few times a year. We have one, and a 5500 on board. I use the Honda a lot because it is whisper quiet and will run everything but the AC. It runs the TV and Tailgator Satellite stuff in the evenings too.
We use it around the house when the power goes out to run our freezers as well.
Anyway, run the Honda for a couple hours in the am, use it for your coffee pot and such then shut it down.
You should be good to go after that, with the charge from the truck trickling as you drive.
My son has one of the Harbor Freight 2k inverter gennys and he swears by it...cheaper than Honda...an option...

We sometimes stay for 10-12 days of grid, so I also have a Big Buddy Propane portable propane heater that is certified for indoor use. I am a very, very light sleeper and the forced air turning on and off will wake me up, the Buddy heater runs for 8 hours on low on a single 1lb propane cannister...and will use no power at all. It has a built in fan that runs on D cell batteries, the are good for about 12-18 hours, but you don't have to run it.
Solar is the ultimate answer for boondocking tho....it is also an entirely different subject. Two years ago I added 500 watts of solar to the roof of our 35 ft. toyhauler and have never regretted it...

Enjoy your trip....sounds like a bucket list item for sure.

 

[bigceltic]

I looked at the Harbor Freight 2000W generator but found one cheaper at JEGS https://www.jegs.com/i/JEGS/555/819...VrkhEJUKPo39PggkV3c6HCWaVLIXXMnsaAiEnEALw_wcB It is supposed to be as quiet as the Honda (I can't say for sure) but it is very quiet.

 

[Dan_69GTX]

I'm not saying don't buy anything but a Honda....but....for these other gen sets try finding
- service manual
- common replacement parts
- how long can they run above "rated" load up to the max output (honda is 30 min).

And yes, the truck would be a "trickle charge".

 

[Tuesdak]

As this is a bucket list item you can sell the items (Generator, surplus batteries) after the trip. So get good ones before the trip as prices in AK are high.

If you break down and have a couple days dry camping waiting on repairs you are prepared for it.

A good used generator is a better bargain than the Harbor Freight "Is it going to work when I am in the middle of nowhere and absolutely need it?" If you get a new good generator put some hours on it and make sure it doesn't have any early failure defects. I would be unhappy to find out I drug dead weight around for that entire trip and it did not work - ever. Staycation at a very local campground would be a good way to work the bugs out of Dry Camping in general.

Although Quiet is preferred for camping: I keep a 1988 Homelite commercial engine genset around for backup power duty and more. Not many cheap sets can claim 25+ year hard life. (The combined age of my 3 gensets is older than my retired dad. 2 are Onan.)

Although Golf Cart batteries are recommended you need to measure and see how they would fit before committing to them.

 

[mwilson]

A couple of things before I start the day....

1) I bought a bigger vented battery carrier so I could use Group 31 stud post truck batteries....two reasons, the first being the increased capacity and the second being that I have an unlimited supply of core batteries at my disposal. Trucks typically have four batteries and should all be replaced at the same time. At least 50% of the cores turned in are perfectly ok, they either need a proper charge or three were being drawn down by one bad one. I have one core battery that is six years old and is still as good as the day it was sold.

2) Installed a switch and relay to cut the power to the battery when plugged into shore power for any period longer than a day. That's why the above battery has lasted six years. I ruined a couple of batteries before I learned that little trick.....
Plus I remove the battery when I winterize the trailer and store it in a heated garage.....

3) I have dry camped with furnace, fridge and water pump running for two consecutive nights in 30 degree weather. But my furnace is smaller and battery is bigger than the OP's.....

So were it me I would simply install the biggest Group 31 I could find in the camper and go have my bucket list trip....

BTW, I do carry a Honday EU2000i genset.....because the wife want her hair dryer to work and I want my coffee........other than that the trailer provides everything we need when unplugged....

 

[GAmes]

There will be an occasional night of pulling over to the side of the ALCAN highway and spending the night. The rest of the time we'll be at a campground with full hookups.

The best part of the trip is staying at the provincial campgrounds along the Alaska hwy, IMO. Quiet, uncrowded, inexpensive and almost always next to a lake. There isn't a big electrical grid in Canada, so most of the campgrounds will be running off diesel powered generators. They aren't always running but the price remains the same. Don't expect to see a lot of 50 amp plugs, and there isn't always 30 amp either. Carry extension cords and adapters.

One other thing. Be sure your exhaust brake is working.

 

[AChaulk]

Wow guys! Lots of great advise. Really appreciate the input from everyone.
I think I'm going to do a two pronged approach of getting two Trojan T-105 6v batteries and a Ryobi 2300watt portable inverter genset. (This generator is supposed to be almost as quiet as the Honda 2200 model, hopefully.) That combo should be enough to keep me alive at night. I'm hoping that I'll be able to use the genset at my house if needed to supply the fridge and a fireplace fan if I lose power over the winter months.

I mostly don't want to install a lot of nice upgrades on the 5th wheel because I'm not thrilled with this particular rig and may sell it. Mostly because I discovered a few months after I purchased the rig that mice had been chewing on the wiring in the belly of the beast when the prior owner parked it in his horse barn. All the horse food n such kept the mice happy while they partied in the 5th wheel.

BTW... For those of you that have pulled over and dry camped along the ALCAN route... Did you find a lot of other campers around you running their generators all night? I'll be traveling with four other couples in their 5th wheels and they have decked them out with thousands of dollars in solar and battery banks. At least one of them will be upset if they hear my generator running after they spent the big bucks for a quieter system. My thinking is that there will be numerous other campers in our area running their generators, so what difference will mine make.

Great thread! Thanks again.
Al buquerque

 

[GAmes]

There isn't any need to run the generator at night while you sleep, and if you are staying in a provincial campground there are quiet hours in some of them. Just an FYI, the Alaska Hwy hasn't been called the AlCan for years.

I bought a cover for my generator and a luggage carrier from Harbor Freight. My 5er has a factory installed hitch receiver and the generator rode just fine, strapped down of course. My electrical cord is in the rear of the camper, 30 amp, so I only needed a 30-15 amp adapter. There will be a lot of dust in the construction areas (and there will be some) so take a spare air filter or two.

 

[Tuesdak]

I would look into gensets with more research. Ryobi made a turd of a weed wacker like 25 years ago. Again buy a Honda used to save money. Home backup is separate from RV - worry about the trip first and don't bring a larger fuel hungery genset on the trip because it's what you need to power things at the house.

Any others in your caravan bringing a genset? Solar isn't perfect. You may be getting a plug in your genset from another RV to help charge batts...

Regardless you use the genset when you need it: Bulk charge batteries in the AM while you make coffee. Then unless you have a specific 110v appliance need don't run it. Don't idle it. Battery charging is something to look into. Batteries take the most amps during bulk charge with a converter that steps up the voltage. Topping off a later charging stage where batteries take lower current and a long time to complete can be done with the truck and driving - again upgrade ground and charge wire. Topping off with genset wastes fuel unless you need the microwave in the evening.

I have other loads that drain my batteries, but, I can get by with 3-4 hours of generator a day to charge back up if I am stationary in the shade where solar is INOP.

Yeah Honda's are quiet at idle. Put a load on them and my Onan is the same generator running noise. Thus low load is the only advantage. But don't idle it just because you think it's quiet and this is the best respect you can show for other campers.

The converter having 3 charging stages is critical. What make and model is yours?

There is a lot to a battery and charging. Understanding it even a little makes all the difference in the world to set expectations and truly enjoy the full capabilities of a 12v RV system. Further reading about solar and batteries from someone way more experienced than me:
https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/