Run Refrigerator While Traveling With Inverter?

**gbkims** · 12-23-2018, 08:59 PM

Originally Posted by howson

What about the Xantrex Freedom XC? http://www.xantrex.com/power-product...reedom-xc.aspx Is this a possible replacement for the WFCO in my 315RLTS? I've read just about every post I can find in the forum on the subject of an inverter but I admit to still being a bit confused on what I need. (I also don't want to spend a bazillion dollars on the solution, too!)

The Freedom XC has built-in automatic transfer switch (ATS), will convert and invert and it will charge lithium batteries. (I'm thinking Battle Born's at some point.) I *think* this device will still require a run of thick-gauge wire from the batteries on the trailer's tongue back to enable the inverter, right? Between the charging current provided by the truck and the robustness of the Battle Born and their long run times I *think* this will work. What am I missing?

Howard,

I think you found a gem!
Yes it'd replace the WFCO converter.
If I knew about it earlier on I'd probably have bought one.
I see it has several battery types and charge levels to choose from.
Klenger had used just a Xantrex charger to replace his and like the brand.
https://www.mygrandrv.com/fo...l=1#post179432

Couple the Freedom XC 1000 with couple of Battle Born and you'd probably have a working solution.
I'd try to figure the frig's Ah draw in an average driving day to get a idea of how much of the battery capacity is used while driving before you hooked up to shore power again for full recharging of the Battle Born's.

**howson** · 12-24-2018, 04:53 AM

Originally Posted by JColeman

I understand the desire for the set it and forget it solution, but I want to point out that in using my suggestion you would not be traveling with pressurized lines.

OK, now I think I understand. You're right--that could be a workable solution. When I stop I could turn on the propane. The refrigerator will switch (once the lines pressurize and gas makes it to the appliance) over. Then when I get ready to leave I need to remember to off the propane at the bottles.

What it comes down to the cost of a given solution versus convenience. I also have to consider weight, as I've got my 315 already close to it's GVWR.

Nothing is off the table at this point. Thanks for the follow-up.

**howson** · 12-24-2018, 07:03 AM

Originally Posted by gbkims

I'd try to figure the frig's Ah draw in an average driving day to get a idea of how much of the battery capacity is used while driving before you hooked up to shore power again for full recharging of the Battle Born's.

Here's the numbers I'm working with right now. I'd appreciate your (or anyone else's) review and constructive criticism.

Max current from my truck's 7-pin is 10A (based on @ncitro's numbers from post 19). I'm counting on this circuit to power the DC side of the refrigerator's circuits. What I mean by that is I am not subtracting this draw over time from the batteries (while driving). The DC circuit on the refrigerator's main board has a 3A fuse.

I'm figuring a worst-case refrigerator duty cycle @ 70%. Dometic's service manual says the unit will draw 420 watts @ 3.5 amps on the 120V circuit (+/- 10%). In a perfect scenario that's 35A of 12vDC (more likely close to 40a with loss in the inverter, voltage drop in the wiring, etc). That's very close to what @klenger calculated for another forum member about a year ago in a similar scenario (but different refrigerator). It's also exactly what @Colan wrote in post #3 of this thread. Using a Kill-A-Watt I measured (see post 13) 3.39A, so 406 watts or 34A of 12vDC.

The maximum time I'm expecting the batteries to power the refrigerator is 10 hours. At a 70% duty cycle (again, worst-case scenario) that means the batteries are working 7 hours @ 40A.

Battle Born's are rated at 100aH and according to many testimonials they will provide 100% of that rating.

According to the batteryweb website, in ideal temperature conditions and ignoring voltage drop over time, a 100aH 12V battery will provide 5A for 20 hours. I'm over-simplifying it, but that's 10A for 10 hours, 20A for 5 hours, 40A for 2.5 hours. Connect two batteries and it doubles the time, so 40A for 5 hours. Go to four batteries and I get 40A for 10 hours. Since the worst-case scenario is 7 hours, I could go with three Battle Born batteries and get 7.5 hours with zero additional capacity. (What if the DW wants to run the microwave at a rest stop?)

I *assume* (terrible word) the Battle Born's will fully recharge overnight while hooked up to shore power.

The math is not encouraging, likely because I've set the duty cycle quite high. Most places I've read estimate a 33% duty cycle, but I'm not sure they are accounting for a scorching hot RV being towed on a summer day in the south. And four(!) Battle Borns...big $$$$. The 2000W Xantrex is another $670. Yikes.

Thanks for reading and I look forward to any and all responses. I want to get this right the first time.

**Gyro Gearloose** · 12-24-2018, 07:09 AM

Howard,
Back in post #42 , my question was base on running AC back to the trailer from the truck and connecting it to the trailer charging system.

When I suggested this I was thinking of the Xantrex Prosine inverter/charger in my bus. When I was dry camping with the bus and needed to charge the batteries, I would run the charger with my Honda eu2000. The charger will charge at 100Adc but my Honda would not provide enough power to run the charger at that current, so I limited the charger to only 60Adc and everything worked fine.

Not saying this is the correct way, just staying with the theme I suggested. Run AC from the truck inverter to the Freedom and it will go into charge mode to charge the batteries. (May have to limit the charge rate for the trucks inverter) You will also get charging from the trucks 7way. Anyway the AC power wire to the trailer will be much smaller than the 200Adc the Fredom can pull.

Freedom can power refer when stopped, but may draw down battery. Again, gas when parked. (maybe an ignition controller gas valve?)

You said other things aren't off the table, so throwing out some other thoughts.

**ncitro** · 12-24-2018, 07:16 AM

That math seems right, definitely a large investment. Here’s a guy on a truck forum I read discussing upgrading the charging circuit:

https://www.ford-trucks.com/forums/1...ver-hitch.html

**howson** · 12-24-2018, 07:33 AM

Originally Posted by Gyro Gearloose

Howard,
Back in post #42 , my question was base on running AC back to the trailer from the truck and connecting it to the trailer charging system.

When I suggested this I was thinking of the Xantrex Prosine inverter/charger in my bus. When I was dry camping with the bus and needed to charge the batteries, I would run the charger with my Honda eu2000. The charger will charge at 100Adc but my Honda would not provide enough power to run the charger at that current, so I limited the charger to only 60Adc and everything worked fine.

Not saying this is the correct way, just staying with the theme I suggested. Run AC from the truck inverter to the Freedom and it will go into charge mode to charge the batteries. (May have to limit the charge rate for the trucks inverter) You will also get charging from the trucks 7way. Anyway the AC power wire to the trailer will be much smaller than the 200Adc the Fredom can pull.

Freedom can power refer when stopped, but may draw down battery. Again, gas when parked. (maybe an ignition controller gas valve?)

You said other things aren't off the table, so throwing out some other thoughts.

Thanks, Pat. Every choice has merit but there's always drawbacks.

The EU2200 is nearly $1K (!) on Amazon. While a workable solution, the generator becomes one more thing to take care of (maintain) and I'd want ethanol-free gas for it. Running a generator in the rain is a no-no, too, so I'd have to find a way to protect it from the weather. (It *will* be raining when I need it!) As you may recall from one of the first posts in this thread, minimizing the logistics associated with going from place-to-place is a very high priority.

The more I ponder modifying the truck the less I want to mess with my essentially new, stupid-expensive truck. If there was an OEM or well-established after-market setup ready to install in the truck I'd be much more inclined to consider it. Swapping out the WFCO in the trailer and installing a few more batteries (in parallel) is more palatable. Still reading and looking at options, but if I had to choose right now that is what I'd do. (Until, as noted previously, I consider the $$$!)

**Gyro Gearloose** · 12-24-2018, 08:01 AM

Originally Posted by howson

Thanks, Pat. Every choice has merit but there's always drawbacks.

The EU2200 is nearly $1K (!) on Amazon. While a workable solution, the generator becomes one more thing to take care of (maintain) and I'd want ethanol-free gas for it. Running a generator in the rain is a no-no, too, so I'd have to find a way to protect it from the weather. (It *will* be raining when I need it!) As you may recall from one of the first posts in this thread, minimizing the logistics associated with going from place-to-place is a very high priority.

The more I ponder modifying the truck the less I want to mess with my essentially new, stupid-expensive truck. If there was an OEM or well-established after-market setup ready to install in the truck I'd be much more inclined to consider it. Swapping out the WFCO in the trailer and installing a few more batteries (in parallel) is more palatable. Still reading and looking at options, but if I had to choose right now that is what I'd do. (Until, as noted previously, I consider the $$$!)

I hear you on not wanting to modify the stupidly expensive truck, it looks like a nice one!

I was not suggesting using a generator, I was suggesting that an inverter in the truck acted as a low power shore power for the RV inverter/charger while traveling. Maybe I didn't state it well? For me, I guess I'm just not a fan of running massively larger wires from the truck to the RV.

Yes, so many options and it seems none of them are easy or cheep!

BTW, I also agree with your math...

**DaveMatthewsBand** · 12-25-2018, 10:56 AM

Just do what I did, install $10k worth of solar and lithium and run the Fridge on that, indefinitely, without a generator.

Easy peasy

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**howson** · 12-30-2018, 04:19 AM

This is timely--Mike Sokol is going to be testing exactly what I want to do and with a Xantrex Freedom XC-2000 no less! This is a link to his newsletter: https://www.rvtravel.com/rv-electric...ue-14-welcome/

I'll be very interested to read his results.

**DaveMatthewsBand** · 01-05-2019, 09:24 AM

Cheap solution...
move your food from the fridge to a large thermoelectric cooler that is powered one of your existing 12v powered ports inside the truck. Would take 10 minutes tops. Done.

https://www.amazon.com/dp/B01LYL17ZW..._cOnmCb6480CK0

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