New to 4WC and RV in General

[RallyRock]

Hi Everyone,

Im new to the forum, but I’ve been reading for the last year or so. First of all, great site and you all really helped me make some decisions. Without boring you with my story, I’ll just say that my journey started about six years ago with an interest in truck campers and gettin out on the open road. Been traveling for work internationally and now I want to give my beautiful country the attention it deserves.
About three years ago bought a Ram 2500 6.4L with about 2900 lb payload. It’s a beast and I love it but I am pretty limited on TCs if I don’t want to push it to the limit. That leads me to where I am today because about a month ago I took delivery of a brand new Hawk Side Dinette. It’s fantastic, leaves me headroom for payload and my wife loves it as well.

Couple things I’m still learning and struggling to understand though. The Furnace and learning how to use my fridge better so it doesn’t eat up my battery.

For the fridge, At the beach with sun I’m cool and it gets plenty of power. But recently camped at elevation with too much shade and I saw my battery voltmeter dropping below 12.6 first night. I thought that you didn’t want to get that low so I just shut the fridge off and we used coolers for the most part. I’m setup with a 160w Solar panel and 2x6 volt batteries and was looking into a portable solar panel for the next time. What am I doing wrong here? FYI, I did charge for a couple nights on shore power and I put cold drinks inside to start the weekend, but seems like I ran out of juice too quickly.

Next is the furnace. I stayed warm with the thermal pack but I tried putting the furnace on and all it was doing was spitting out cold air. No idea what I’m doing here lol, i ran the stove burners on to get air out of the lines, I put up to 72 degrees on the thermostat, waited a couple minutes to see if warm air would blow but I got nothing. So I just said screw it we can just bundle up which worked fine. Again, what am I doing wrong here.
Here’s my options:
isotherm 85 ac/dc
Flush stove and fridge
no AC
side dinette
furnace
outside shower
tankless water heater
king bed

This thing is awesome and I can’t wait to get it out on the road for longer trips soon, but what do some of you more experienced guys think of the two situations I had?

RallyRock

 

[NRVhawk]

Hey RallyRock,

Welcome to the forum. Your rig looks very nice - I expect you'll have lots of great adventures in it. I can relate to the learning curve you're going through. When I need a good laugh, I just think back to the first cold, clueless night in my camper. I made a lot of rookie errors.

A few thoughts: at best, using the battery voltage as a measure of state of charge is good as a approximate indicator, particularly if you're only measuring with a precision of a tenth of a volt. It also depends on whether you're measuring the voltage at open-circuit or under load - best to measure open circult (no load) so that the internal resistance of the battery doesn't drop any voltage. A lot of campers add a battery monitor like a Victron or Trimetric that monitors the current leaving the battery. Since you program the monitor for the capacity of your battery in Ahr, it tells you directly how much charge you have left.

Having said that, 12.6 volts doesn't sound all that low. I think that corresponds to somewhere from 80 to 90% charge in an AGM battery, You didn't mention what your total battery capacity was in Ahr, but the Isoltherm 85 draws about 4 A when the compressor runs. If you have 100 Ahr of battery capacity, then having the compressor run a total of 2.5 hours over the course of the night would drop the battery down to 90% charge.

Unless it was pretty warm where you were, two and a half hours of compressor use sounds like a lot. However, the fan inside the furnace also draws a lot of current when it runs. I don't remember exactly what the current draw is, but it's similar to the Isotherm fridge. So if the furnace fan ran a lot because you weren't getting hot air, that would certainly pull the battery down a lot.

As far as the furnace goes, there are many, many posts on this forum about troubleshooting that, so a search might be in order. If your furnace woes occurred at high elevation, you would probably suspect the sail switch. There's a good video on the FWC support web pages about troubleshooting the furnace. Most often, a quick fix is removing the flex hose behind the furnace grill.

Another thing to be aware of is that the gas regulator for the propane has a safety feature that throttles back gas flow if it experiences a sudden drop in gas pressure that could occur from a broken gas line. If you open the valve on the top of the propane bottle too rapidly, it'll trigger that safety feature. To clear it, you need to shut the valve on the tank, remove the fitting from the tank (to relieve any pressure in the line in order to allow the safety valve to reset), reconnect the fitting to the tank, and then open the tank valve slowly. Possibly insufficient gas flow due to a triggered safety cut-out might have prevented the furnace from operating properly.

Hope this helps. I expect that you'll get a lot of other helpful suggestions.

- Rusty

 

[NRVhawk]

RalleyRock -

One more thought: There's no hard and fast rule that says that you shouldn't run an AGM battery below a specific state of charge.

I remember an informative, thoughtful post by rando a few years ago that pointed out that there is a tradeoff between depth of discharge and lifetime (at least for an AGM battery). The basic idea, much better explained by rando and with data, was that if you consistently draw your battery down to something like 75% state of charge, you can expect a certain number of charge cycles before the battery dies.

If you consistently draw you battery down to 50% SOC, you'll get a different number of cycles over the lifetime, and that number will be less than what you get at consistent 75% drawdown.

So the tradeoff rando suggested was that you might be willing to accept routinely discharging the battery more deeply if you're willing to budget more frequent battery replacements, or if you only use your camper a few times a year.

My apologies to rando for mangling his explanation. I tried searching for it so that I could link to it, but there are so many posts on batteries (including posts by rando) that I couldn't find it. But it certainly opened my eyes and made me a lot less AR about having to occasionally draw my AGM battery down more than usual if I needed to. Last year I made the conversion to LiFePO4 and have been very happy with that with over 60 days of camping so far.

- Rusty

 

[Wandering Sagebrush]

RallyRock, welcome to Wander the West! I think Rusty is correct. It seems that getting the furnace to light and stay lighted is plaguing a number of folks, and there are multiple threads on the topic.

Our search engine isn’t always helpful, but Google can help find topics. Try searching with a Google search similar to this: site: wander the west.com “furnace won’t light”.

 

[Mighty Dodge Ram]

Good advice re: the battery monitor. I’d be surprised if your 6v batteries ran out of power that soon. They’re typically golf cart style deep cycle and designed to be drawn down. I have the same batteries in a 32’ motorhome and I’ve never run them down beyond usable power…no solar.

 

[RallyRock]

Hello Sagebrush and Rusty. Thanks for the welcome and your thoughts. I have already learned my first lesson, make sure the damn fridge is closed and latched before driving away…. Thank God none of the cans in there exploded as they flew across the camper and thank God I kept my back window open so I can look curiously at a door hanging open not 5 minutes after I drove away. Also upgraded my tiny step stool to a Little giant three stepper. It’s awesome. Other than that it’s been pretty smooth sailing apart from a couple minor things here but can’t wait to put some more stories on the camper.

I’m busy diving into my owners manuals and I notice that theres nothing on the battery capacity. All I know is it’s 2x6v. I’ll have to open up the compartment and get a better look. I thought about lithium but I’m waiting for solid state batteries to penetrate the market before making any significant investment there. For now I’ll just grab an extra Solar panel and be energy conscious. For the fridge, just looking at the manual it says it consumes about 380 watts/24hr but man I need to understand these formulas better. I get that somehow you know it’s 4A power draw and I trust it’s close enough and I just need to see how big the batteries are to estimate how much room I have to work with.

I was definitely looking at the voltmeter under load. Just so I’m sure what you mean, are you saying turn everything off and then see what that number shows as a better indicator? If that’s the case then yeah I was being too conservative! I was thinking 80% loaded which is 12.6 volts starts to degrade the battery so I was trying to stay above that. However, sounds like more of a battery life thing and not so much of a battery getting acutely damaged beyond normal use. It makes sense what you wrote about rando, I think I need to brush up on my electrical knowledge. I can put Teflon tape over fittings, screw in a screw, hammer a nail and run a table saw, but electricity isn’t my trade lol. If you do run into that post though please let me know!

As for the furnace, I was told by the dealer to just pull that ducting out if the furnace gives me crap (in so many words). I’ll give that a try and in the meantime check the sail switch and go through the steps you mentioned. Sounds like everything I need has already been posted so I’ll do more diving through the forum and it’ll be a good way to start learning the little things.

I’m not really concerned something is wrong with the camper, mostly just trying to understand how things work and introducing myself, tons of fun! You know you made a good choice when the wifey loves the camper as much as you do Anyway, thanks again for the welcome and input, if you think of any other good places to start let me know!

 

[RallyRock]

Good advice re: the battery monitor. I’d be surprised if your 6v batteries ran out of power that soon. They’re typically golf cart style deep cycle and designed tone drawn down. I have the same batteries in a 32’ motorhome and I’ve never run them down beyond usable power…no solar.

Yeah, I had a feeling I was just being cautious but thought I’d ask before I went too far down the rabbit hole. So there’s a Blue Sea meter that came with the camper. Not the solar indicator, the one next to the charge ports. Isn’t that a battery monitor?

 

[pvstoy]

Yeah, I had a feeling I was just being cautious but thought I’d ask before I went too far down the rabbit hole. So there’s a Blue Sea meter that came with the camper. Not the solar indicator, the one next to the charge ports. Isn’t that a battery monitor?

Most likely that is just a battery gauge that just shows what the voltage is currently. Here is a link to the Victron 712 battery monitor that will show you better what the current state of your battery is.

https://www.victronenergy.com/battery-monitors/bmv-712-smart

Don't forget your camper is new and have 100 percent support and repairs through FWC for things that are not working for you.

 

[RallyRock]

Thanks pvstoy! I’ll have a look at that.

I think I’ll keep an eye on the furnace to see if I need to bring it in but hopefully not. Thanks for reminding me that point though, no doubt if I feel like something isn’t right I’ll give them a shout. They are solid from my dealings with them so far.

 

[Casa Escarlata Robles Too]

Welcome to the cult,also.
I have had issues with the heater at times.
There are times it takes a few tries to get it to throw out the heat.
Sometimes it's just easier to run the stove for a few minutes.
Frank

 

[PaulT]

If you find you have two GC type batteries & want to go to LiFePO4 batteries, Battleborn makes the 100 Ah batteries in the GC2 size.
I replaced my factory AGM GROUP 24 batteries with a pair of them and while it was a tight fit in my front dinette Hawk, they did fit.

It is nice to have 200 Ah to draw down rather than just effectively 75 Ah.

Paul

 

[ckent323]

RallyRock,

Welcome to the WTW forums.

Determining the state of charge (SOC) of your batteries using a voltage monitor is not accurate.

As previously suggested by others above, I strongly recommend installing a good shunt type battery monitor such as a Victron BVM-712 or equivalent.

I also recommend that you do not routinely draw your AGM batteries down below 50% SOC and always fully recharge them before drawing them down again (routinely under charging AGM and Lead Acid batteries before discharging is one of the causes of sulfation which reduces battery life).

For more on batteries here is a great resource:

https://batteryuniversity.com/articles


Also, in case you are not familiar with Solar Panels, if you get any shade on any part of your solar panel the output from your system can be seriously reduced (depending on the panels as well as how they are connected). So beware of shade from roof top racks, trees, power poles, etc.

If you have an Overland Solar or Victron MPPT Solar Controller with bluetooth you should be able to monitor your solar power production from a smart phone (or laptop).


P.S. The battery monitor also serves as a diagnostic device. You can turn the various items drawing electricity on (or off) individually and see what they actually draw. If you have a device pulling more than expected you may be able to isolate it and then trace down the problem - bad connection or whatever.


I hope this is helpful.

Craig

 

[RallyRock]

Welcome to the cult,also.
I have had issues with the heater at times.
There are times it takes a few tries to get it to throw out the heat.
Sometimes it's just easier to run the stove for a few minutes.
Frank

This is the kind of cult I can get used to! What impressed me was that I was in 30 degree weather recently and the insulation pad kept us nice and warm. No need for a furnace at all. When I was tenting it I was always either cold or too hot in the mummy bags when it got down to those temps. What an upgrade this is.

 

[NRVhawk]

RallyRock,

Found the post by rando on the tradeoff between depth of discharge and battery lifetime. It's post #217 in this thread:

https://www.wanderthewest.com/forum/topic/13230-i-need-more-power-scotty/page-22?hl=%2Bcharge+%2Blifetime#entry171105

Unfortunately, it looks like the link to the graph that he posted illustrating the tradeoff is broken. That whole thread has a lot of useful info, but it's long and can quickly lead you down a rabbit hole.

As you can read, rando was comfortable drawing down to 30% SOC because he concluded that the resulting decrease in battery life was acceptable to him. Craig, on the other hand in the post above, recommends not going below 50% routinely. When I used AGM batteries, I never went below 50% and usually not below 70%. I was hoping to make my battery last as long as possible, so I was pretty conservative. Not too difficult in my case because I didn't have a 12V fridge, so my only big current draw was the furnace.

As it turned out, I replaced the AGM battery after 5 years of use, but not because of decreased performance. Instead, I was tired of the unreliability of my 3-way fridge, so I put in a compressor fridge along with a lithium battery for more capacity (and lower weight).

- Rusty

 

[RallyRock]

If you find you have two GC type batteries & want to go to LiFePO4 batteries, Battleborn makes the 100 Ah batteries in the GC2 size.
I replaced my factory AGM GROUP 24 batteries with a pair of them and while it was a tight fit in my front dinette Hawk, they did fit.

It is nice to have 200 Ah to draw down rather than just effectively 75 Ah.

Paul

Ok so finally got into my battery compartment today. I’ve got two USAgm 2224 deep cycle 6 volts.

https://www.usbattery.com/products/us-agm-batteries/us-agm-2224/

Does this mean I’ve got 224 AHs of use available to me assuming I don’t go below 50% and I’m not charging the battery at all?

 

[RallyRock]

Thanks for the post ckent323. I think it’s a good idea to invest in a battery monitor like you pointed out. It’s too bad that isn’t available from the factory, just seems like an option I would have picked right off the bat! However, do not mind installing my own either and saving a few bucks

And thanks NRV, here I was thinking I’m going to ruin the battery but dropping below 50%. It’s reassuring to read. However, everybody really seems to like these LiFePO4 batteries so one day when it’s time to consider an upgrade I’ll give them a look! Maybe something will come out that’s better by that time!

 

[RallyRock]

Also ckent323 appreciate the battery link. Already reading through just to understand this stuff more.

 

[PaulT]

As 6 volt batteries, they are wired in series to get 12 volts at 224 Ah. If you read the referenced pdf file, you will see that you should discharge only to 50% meaning you have 112 Ah to use.

Paul

 

[Mighty Dodge Ram]

My comment about 6V GC batteries designed to be drawn down was not to suggest that you can “empty the bank”, but rather that these batteries are designed and built for longer and lower discharge compared to starting batteries. The 50% threshold is still good advice. Your typical 12v lead acid “deep cycle” batteries (most are marketed as marine) have anywhere from 90 to 120 amp hours, at least the ones I’ve seen. That gives you 45-60 useable ah. Your 6v GC batteries combined to make 12v give you approx 225 total ah, around 112 usable ah. Even though they’re much heavier and bulkier than one 12v unit, you’re way ahead of the game in terms of available power. And they’re typically serviceable which can increase the lifespan. I need to replace the GC batteries in my motorhome soon. My local Costco has them for $100/ea. I don’t service them at all, my bad. But I get 4-5 years of moderate use out of them which makes them a relative bargain.

All of those considerations make them a viable choice for your unit, especially if your camper originally came equipped with them. Get yourself a good battery monitor, as suggested, and then go ahead and use them with confidence.

 

[RallyRock]

As 6 volt batteries, they are wired in series to get 12 volts at 224 Ah. If you read the referenced pdf file, you will see that you should discharge only to 50% meaning you have 112 Ah to use.

Paul

Ah ok got it thanks.