Yeah, I missed the 20% but my statement still stands. At the time of his issue, he only had 270ah, now he has twice that. But this is also about amp hour management, and management of expectations... knowing the system and its charging efficiency so you're not left in the "dark." When his solar isn't operating at peak (cloudy/rain), then his generator comes into play. Running down your batteries to a low SOC, then expecting whatever charge from the truck alternator to fully charge your trailer batteries isn't normally realistic, especially during a relatively short trip. Even if a fella is getting 50a of charge, as you mentioned, to charge the 540ah battery bank that's at 20% SOC will still need over 8 hours of charging time (again, assuming the alt survives). Not a situation I would call reliable and outside of a cross-country trip of many hours, it's not always reasonable to expect your truck to fully replenish your RV batteries from a low SOC at any realistic charging rate.

I've never advocated for the OP to get an 18amp charger, or that he sets up his system the way I have mine. I merely shared my experience and advocated that he does need a DC-DC charger of some kind. I also shared that at least on my truck (the longest configuration), it's possible to get adequate voltage at the 7-pin at the truck bumper, which might save him some money and time. All the warnings about voltage drop at the bumper have not proven true on my truck, and I've had no issues keeping my lithiums topped off with my measly little 18a DC-DC charger and power from the 7-pin. But I built my system to accommodate my needs. I think the OP needs to investigate ALL the possibilities and then make his decision. He needs to build his system according to his needs, and wire it according to those needs and what's comfortable for him. If that's coming off the bumper, fine. If that's coming off the truck battery, also fine. Doesn't matter to me.

 

My 560 Ah LiFePO4 battery bank gets zero charge from the tow vehicle. The solar on the roof has been good enough to get to 100% state of charge. When my absorption refrigerator dies and I switch to a residential refrigerator, I may add a DC-DC charger but it would be a low amp one, maybe 9 amps.

 

Yup, it's what will suit your needs. By the way, when my absorption fridge dies, I think I'm gonna replace the cooling unit with an Amish one. I hear they work better than OEM and I'd like to retain the propane capability.

 

The residential replacements are somewhat lighter in weight, have much more internal volume and cool better. But I'm not in any hurry.

 

I did a 40amp by Renogy. I highly recommend using a high power relay (stinger 80amp works well) to an upfitter switch to control the power to the back of your truck. I also agree with using an Anderson 120 connector. It’s so easy. Not a hard job to do and there’s plenty of room to run the wire. I would think a truck shop might do the work for you. Any towing place or place that installs rails for 5th wheel hitches. The hardest part is crimping the Anderson crimps. Even with a pneumatic crimper they were tough.

 

Good to read your success, thanks
After reading the instructions to set up the "Engine shutdown detection setup with VictronConnect”, section 5.2 in manual, I didn’t feel like iterating through the process to find the settings for my vehicle and trailer ….so I just used the tap wire method. Would you mind sharing the 6 Engine shutdown detection charger parameters [eg; Alternator type, Start voltage (Vstart), Delayed start voltage (Vstart(delay)), Delayed start voltage delay (tstart delay), Shutdown voltage (Vshutdown), Input voltage lock-out] that you say works so well as we have similar trucks. Thanks. I figure that data would get me 99% to be able to use the auto detect.

 

 

Thank you so much for the parameters…when the weather permits, I’ll give autodetect a try..

 

6 AWG is fine for 30 amp. The Orion only accepts 4 AWG, which is fine for 50 Amps.

 

I'm in the middle of installing a new Orion XS 50A now.

Once complete, we'll have a 50A Phoenix for charging on AC and a 50A Orion for DC, we use 200W of folding panels for solar since we mostly camp in shaded areas and seldom even use them.

About 5 years ago I ran a 1/0 circuit from the front of the trailer to the back, because at the time we were running the factory converter with a LifeLine AGM on the tongue, happens that the circuit is 2 feet longer than the one I ran in the truck for the existing DC charger. So yesterday I removed the 1/0 from the trailer and began the process of installing it in the truck.

I'll have a dedicated 1/0 (+/-) circuit ran directly from the truck battery, through a 70A Blue Sea breaker mounted at the battery, back to the 175A Anderson plug at the hitch, then a 1/0 circuit ran from the trailer tongue to a set of power poles located approximately 3 ft from the charger, then 4 AWG from the power poles to the charger. I should be able to get all the power the Orion has to offer.

I was holding off since I have limited space on my equipment rack, but it turns out that the new XS is smaller than my current 30A, so I pulled the trigger yesterday.

 

That color matched cable routing is SNAZZY!

 

I installed dual Orion Tr Smart non-isolated 12/12-30 units (the new XS unit was not available at the time I purchased). I pulled #4 wire through an Anderson connector between the truck batteries and the chargers; I get about 45A. I have dual alternators 240A/157A for a total of 397A; not intelligent. I probably could have more current with #2 wire, but I'm happy with 45A and feel that is a safe amount to pull off my alternators. I also have 1700W of solar.

 

Just finished upgrading from a 30A DC-DC charger to the new Victron Orion XS 50A.

Ran 1/0 from the truck battery to a set of power posts about 3’ from the charger, then 4 AWG to the charger (which is the largest size wire it will accept).

It’s pretty impressive how much more compact and efficient this new charger is, and this one is able to connect to my network without the truck being connected, which is worth the upgrade alone.

 

Thank you for the side-by-side comparison. I knew it was smaller but not THAT much smaller. Running cooler it should help keep the heat down in your compartment.

 

Yeah, when Fed Ex handed me the package I thought PKYS had sent me the wrong item