RV house batteries for dry camping?

[Tuesdak]

For your upper battery mount, having cut out that structural steel, I'd recommend a cross brace to go across (side to side looking, forward/aft on trailer), then down at an angle (clear the lower battery) and attach to the frame.

Thanks for the suggestion. I will call a mobile welder to look at doing this.

So let me get this straight: Arctic Fox installed a 60A converter just as far away from the battery as they can get in the rear of the RV. But wait there is more! They used 6 AWG wire to go the 20' distance!

This means when I fire up the converter on AGM's with a 25% discharge I only get 1/3 the output of the converter, ~20A, at 14.4v. Well it's 14.4v at the converter anyway. At the batteries it's low 13's for nearly a volt of loss in the cables. Really need 1/0 Gauge cables for this 20'+ run or move the converter closer to the batteries. No wonder the last set of batteries were murdered.

The Solar wiring is even more fun going from the driver side rear corner panel to mid RV on the passenger side for the old controller then back to the driver side battery location in the front of the RV. At least locating the controller near the batteries can overcome some of the ~36' wire distance voltage loss.

 

[MichaelOverfield]

Thanks for the suggestion. I will call a mobile welder to look at doing this.

So let me get this straight: Arctic Fox installed a 60A converter just as far away from the battery as they can get in the rear of the RV. But wait there is more! They used 6 AWG wire to go the 20' distance!

This means when I fire up the converter on AGM's with a 25% discharge I only get 1/3 the output of the converter, ~20A, at 14.4v. Well it's 14.4v at the converter anyway. At the batteries it's low 13's for nearly a volt of loss in the cables. Really need 1/0 Gauge cables for this 20'+ run or move the converter closer to the batteries. No wonder the last set of batteries were murdered...

Things like that seem to be typical for most RV OEMs. I've had to re-do more things on mine than I care to mention. They just throw these things together as cheaply and quickly as possible it seems. Could you just run an additional set of connecting wires in parrellel to the grossly undersized OEM wires? You could use external conduit, say PVC to protect the wires and not have the hassle of rounting inside with all that would involve. I re-wired my trailer brakes this way, the original wire being way undersized to the point the brakes just did not do much. It was a night and day difference, and much easer to wire in conduit underneath than going inside.

 

[Tuesdak]

External Conduit is the only way to go esp. with the critter's appetite for wiring harnesses around here. I have chopped up extension cords to quick and dirty rewire trailers or add lights. The outer cover is actually an upgrade over OEM single wires on sharp edges left over in wiring holes.


The cost for 40' of wire is like $2.50 - $5.03 a foot. Over $100 in wire alone if I can get it that cheap. $75 each per 25' spool (2 needed) on Amazon at the moment. So I am thinking this is kind of expensive to keep the Converter in a bad far-far away location when 120v is also located closer to the batteries. The underbelly is enclosed somewhat with 3 dirty and 1 clean water tank along the way.

 

[MichaelOverfield]

External Conduit is the only way to go esp. with the critter's appetite for wiring harnesses around here. I have chopped up extension cords to quick and dirty rewire trailers or add lights. The outer cover is actually an upgrade over OEM single wires on sharp edges left over in wiring holes.


The cost for 40' of wire is like $2.50 - $5.03 a foot. Over $100 in wire alone if I can get it that cheap. $75 each per 25' spool (2 needed) on Amazon at the moment. So I am thinking this is kind of expensive to keep the Converter in a bad far-far away location when 120v is also located closer to the batteries. The underbelly is enclosed somewhat with 3 dirty and 1 clean water tank along the way.

Try this wire at Lowes, much cheaper, and having it as added to original should get you plenty of amps with minimal volt drop. It's pretty stiff, but it can carry many amps, and it's pretty cheap. I use the 1/0 guage of this for the inverter power supply with good results.

https://www.lowes.com/pd/Southwire-...d-Black-Copper-THHN-Wire-By-the-Foot/50101584

 

[MichaelOverfield]

red wire is slightly cheaper.. https://www.lowes.com/pd/Southwire-SIMpull-6-AWG-Stranded-Red-Copper-THHN-Wire-By-the-Foot/3135097

 

[MichaelOverfield]

I have found this conduit is easy to work with and pretty cheap as well, offeing good protection for the wires:

https://www.lowes.com/pd/CARLON-Common-3-4-in-Actual-0-75-in-Non-Metal-Flex-25-ft-Conduit/1000380305

 

[Tuesdak]

An update of sorts. The Bogart engineering TM-2030-RV is already saving me genset run time. It hit 25 degrees F last night so lots of heater run time even with the slides in. Was at 40% left in batteries this AM.

So I started the genset and get 30A to the battery set. Some time later like 30min it's down to 17A - at 43%. I have not upgraded the wires from the converter yet. I double checked the charge mode and sure enough the StupidPower Wizard on the converter has switched out of boost into normal mode 13.6v.

So I overrode it back into boost mode 14.4v and 30A shows up. This will cut genset run time in half.

 

[Ozymandias]

JDormine, if you can afford it then do yourself a favour and buy a LiFeYPo4 Battery, it will probably be the last Battery you buy. It has 1/3 of the weight of a Lead Acid Battery and is incredibly fast charging.
And if you have a 100Ah LiPo you can pull out that 100Ah! Not like the Lead Acid that can only safe deliver 50% of its Labeled capacity.
Over here in Europe almost everyone that needs a new Battery for his Camper changes to this Technology now.

For example, I had 3 Lead Acid Batterys with combined 225Ah that weighed 95Kg - now I have one 265Ah LiPo that weighs 40Kg.
So I've more then doubled my Capacity and reduced the weight by almost 2/3.

 

[TFucili]

I am by no means a lithium battery expert, but I have been told LiPo batteries do not do well in the heat. I had a lithium jump pack in my wife's car, and my truck. First, I found hers had swelled to the point of splitting the case, then I inspected mine, and it, too, had puffed up considerably. These were simply riding around in the AZ heat.

 

[MarkEagleUSA]

I am by no means a lithium battery expert, but I have been told LiPo batteries do not do well in the heat. I had a lithium jump pack in my wife's car, and my truck. First, I found hers had swelled to the point of splitting the case, then I inspected mine, and it, too, had puffed up considerably. These were simply riding around in the AZ heat.

Does anything do well in the AZ heat???

I had a similar in issue with one of those small LiOn jump packs but the swelling seemed to be caused from the heat of charging.

 

[Ozymandias]

There is an important difference between LiPo and LiFePo.

The later work always but cost more. Check the technical specs.
They also do not burn or explode like the LiPos.

Tesla for example uses also the Cheepest LiPo Cells that are available.

 

[Ozymandias]

Swelling in general is for a to high rate of charging/discharge.

And please, dont compare some chepo consumer goods with high end industrial grade products.

http://en.winston-battery.com/

 

[Ozymandias]

This is my little power plant.

#ad


From this the Compressor Fridge can run all most 3 Weeks without Recharge in any way.

This tiny Battery is a substitute for 600Ah Lead Acid Bank.

In Cl.8 Overland Vehicles they throw in 1000Ah LiFePos as a substitute for 2500Ah Lead Acid.

 

[Tuesdak]

@Ozymandias That's jaw dropping performance. I would have to see how they do in AZ heat. It's wipers, batteries at 2-3 years, tires.

 

[Ozymandias]

They shouldn't have a problem with it, specs within -45°C up to 85°C.
Check the Charts on Page 2.

http://en.winston-battery.com/index.php/products/power-battery/item/wb-lyp300aha?category_id=176

And what's even better, they can be charged incredibly fast, I could throw 800A Charging in if I would have the ability to.

So we see, a today's RAM with Dual-Alt has the ability to recharged that Battery within ONE SINGLE Hour run time from Zero to Hero.

 

[zb39]

This is my little power plant.

#ad


From this the Compressor Fridge can run all most 3 Weeks without Recharge in any way.

This tiny Battery is a substitute for 600Ah Lead Acid Bank.

In Cl.8 Overland Vehicles they throw in 1000Ah LiFePos as a substitute for 2500Ah Lead Acid.

So what is this exactly, I have dual 440 amp alternates on my Ram 5500. I have 6 6 volt batteries wired in series/parallel with a 4k pure sine wave inverter. Not that weight is an issue but its 500 lbs. Always looking for a better way.....

 

[Ozymandias]

Well I'll do my best to give you that information, what i miss in your post is how many Amp Hours your existing 6x6 Setup has, that would be important for me to provide you a good matching recommendation.

After a lot of googling i provide you some links to australian based companys for the information about what I have, my system is a DIY System instead of an already assembled but more expensive System.
Here you can se how my setup is made step by step, it is german but the pics willnshow everything needed for a DIY LiFePo4. https://www.wohnmobilforum.de/viewtopic,p,2160442.html#p2160442

This are the battery cells, https://www.evworks.com.au/winston-battery-wb-lyp300aha. One LiFePo cell has 3.2V, so 4 of them. Lead Acid has 2V per cell.

Then i needed the BMS System, Headunit 200Amp* https://evparts.com.au/ev-power-bms/ppak-4c.html and Balancer 4x https://evparts.com.au/ev-power-bms/bms-cell-modules/cm400-cell-module.html
*if more then 200Amp is needed then this https://evparts.com.au/dc-contactors-relays/contactor-gigavac-gx14ba.html is a mandatory upgrade.

That's it, what makes also sense and i have is the battery monitor system from Victron Energy (you see the shunt left in the picture i posted above) that tells me EXACTLY the state of the battery, how many AHs are used, how many hours left and much more. https://www.jamestowndistributors.com/mobileportal/show_product.do?pid=51924


But i found a site in the US that might be worth to check out, especially with your existing setup with the 6V Cells https://battlebornbatteries.com/ i would give them a call and get some information about it.
Good Reviews https://battlebornbatteries.com/shop/12v-lifepo4-deep-cycle-battery/#reviews
To me this company seems to have a good knowledge about LiFePo4 and do not just sell it.
The batterys from this company have integrated Balancers/BMS, so no need for them externally like mine have.

And just to say it again, a LiFePo Battery lasts as long as your vehicle, even longer, buy once and forget about it - and also every Amp hour on the label is a usable amp hour - not like the Lead Acid Batterys were itbis only 30-50% usable.
So capacity of the LiFePo4 can be chosen 50% smaller then the existing Lead Acid Setup.
http://www.trailerlife.com/tech/quest-for-power-2/

Edit says you would need an AWG 0 Cabel to charge this battery setup with the full power of your 440Ah Alternators.

 

[zb39]

Thanks for the reply, A lot to think about, I appreciate all your links.

 

[Tuesdak]

Wires to the battery from the converter: Ugly. Finally made some time and got help to knock this out. And the wires are more ugly than I thought!

I emailed Lifeline and asked them what their batteries could take for amps during the bulk charging stage. In other words is moving the converter really going to be worth my time as a project to reduce and get the most from genset run time. I was pointed to the technical manual ... a 100Ah battery can take a 500A in-rush charge current. (These are 220Ah.) Guess we will see what the 60A converter can really sustain in the "bulk" charging stage without a 1.5V drop on the wires. Can't put much of a bigger converter than 70 Amp in without a 20A 120V wiring to it. A 80 Amp converter requires 20A 120V wiring.

I mis-underestimated just how badly the wiring is. No NOT a 20' run like I thought! I noted other RV forums going on about the power distribution center being between the converter and batteries. Verified... It's 20' plus 8' to go to the power distribution center on the other side of the RV and another 8' back to the other side. Plus some height change... It's at least 36' of #6 AWG wire between the converter and batteries. I confirmed this with the voltage drop I was seeing and an online wire gauge calculator. Checking for a bad connection and confirming the wiring below.

Well the first thing we did was remove the power converter and install a 1500W inverter I had laying around in it's place. I put the screws to it and failed. Wouldn't even crank a 750W setting on a heater and the "lights in the RV went out" till the converter tripped off on low voltage. Ok tried a 500W lamp. Constant low voltage alarm, but, lit it up. So 52A 12V draw: 12v at the batteries, 11V at the power center, and 10.5V at the inverter. Yup 36' run of #6 AWG wire eating 1.5V. Only need 100W from it now, but, considering putting it by the converter as well.

Next we put the converter close to the batteries and used 2 Gauge Battery Cable. Well 1 Gauge on the ground as that's all that was in stock locally. Had to thin the wires out a little at the converter as it just wouldn't take wire that big. Pass through storage area. Next is running a new AC outlet for the converter.

In progress as the battery cables are also being upgraded from 6 AWG to 2 gauge. Yes, bypassing the small RV busbars.

Some tools to "roll our own" cables.

 

[AH64ID]

I’m in the process of moving my lifelines, PD converter, and inverter from my TT to my 5th wheel. The battery trays are big enough for the 300AH lifelines so I’m having to make the internal portion of the box bigger.

Luckiy the battery compartment is only a couple feet from the distro center/converter so I’ll be able to reuse most of the previous power cables and avoid a voltage drop. I’m using 2 for the inverter and 6 for the distro center. I’m close enough 6 is plenty for the 55AH charge rate, and my draws don’t get that high.