newbie questions, solar/lithium in a 5th wheel, where to start?

corn18

Village Idiot
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Sep 9, 2021
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With having an 'all in one', what happens when that fails? Does it become 'all is none'? I would rather have individual components so when something fails, then it would be one component.

Something to think about.
This was a concern of mine when I first started my transition to LiFePO4 and solar. I had two inverters (one for residential fridge, one for the rest going through a sub panel), a converter/charger and two solar charge controllers. This turned out to be too complex. But it had lots of redundancy.

DC wiring 290RL rev 1 complex.jpg


I grew weary of trying to remember how all of this worked and there is no chance my wife could operate this system, so I installed the MPII and that eliminated all of the complexity. Sure, I only have one inverter and the charger is now part of the inverter, but now the system is plug and play. It just works. I retained the dual SCCs because I am going to add more panels. I think this simpler system is more reliable than the redundant system. And I get a cool display in the camper.

DC wiring 290RL rev 1.jpg
 

Butcher

Solar Enthusiast
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Nov 14, 2021
Messages
88
Without a doubt. There is no right way but as I mentioned, it's something to think about.

When I look at things, I spend more time designing things thinking what happens if something goes wrong vs what happens when everything goes right. Everything I mount revolves around how I will get to it in the future. It takes double or triple the time to design something thinking about it in a negative way. Designing things that makes testing easier, access easier, bypassing easier, etc.

Everyone knows, if everything is going right, the only thing to think about is how cold to keep the beer.

BTW, that first diagram looks to be poorly planned in many ways. It certainly is a great idea to prove your point that one part does it all. I'm still planning my set up. Although I do not believe I will be going to an all in one, I certainly will be taking the route that my wife would have to either operate one switch or nothing at all. That is probably the highest priority above everything else. You know the saying, happy wife.......
 
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Tony Scott

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Feb 25, 2020
Messages
184
I am entirely new to solar and how electric works in my RV. I have a Grand Design 5th wheel.

I'd like to add lithium/inverter/solar to my 5th wheel and want to do so in stages.

Specifically I want to start by just replacing my lead acid batteries with a couple of 200amp hour SOC batteries and add an inverter. I do not currently have an inverter, but have a converter to convert shore power to DC.

I'm just starting my investigation on what I'll need and would love some pointers. I'd like to be able to power the entire RV off this system when not using 30amp shore power (TV, fridge, lights, phone/laptop chargers, etc..).

Initial questions:
1) I think I'm looking at a device such as a victron multi-plus. i.e. this would house my converter, inverter and charger all in one, is that correct? If so, would I simply replace the converter with this device and wire up the same way the converter was?
2) If I'm not understanding the victron multi-plus correctly, What all parts am I looking at for this phase? inverter, converter, charge controller, batteries, monitor, switch - what else?
3) What about my alternator charging from my truck, what handles that?
4) any links to typical RV diagrams for this type of setup would be great! Any other input would be welcome!
Get wills book and view all his videos. There are a lot cheaper ways then victron, but if you have the money to burn, go for it.
 

AndyRonLI

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Joined
Mar 13, 2021
Messages
118
With having an 'all in one', what happens when that fails? Does it become 'all is none'? I would rather have individual components so when something fails, then it would be one component.

Something to think about.
That is a good point, but you end up with a simpler wiring harness, a single box to hang somewhere, it even includes a transfer switch function. One warranty object , one user support. What happens when Renogy says the problem is with my Victron MPPP and Victorn says the problem is with my Renogy charger. Or they both blame the inverter? The all in one box means only one manufacturer is on the hook for pretty much the whole functionallity.
 

corn18

Village Idiot
Joined
Sep 9, 2021
Messages
475
Corn18, so the Lynx and Gerbo are nice to haves? Not gotta haves?
Yes, nice to have.

For the distributor, it really is not expensive for what you get. A pair of Blue Sea 1000A bus bars will run you $80 x 2 = $160. And I was able to eliminate 4 circuit breakers which cost $35 each. So my old setup was $300. The Distributor is $210 + $35 for 4 fuses = $245. And the install is so much tidier. The hack to get the LEDs working was another $10. So it seems like a no brainer.

IMG_4974.jpg
vs.
IMG_5130.jpg

The Cerbo GX is not economical. It just provides an easy way to manage all the Victron stuff and have a cool display inside. You still need a laptop and dongle to make some changes like LiFePO4 charge profile.

I did get a Raspberry Pi and got that working, too. It is a lot cheaper and fairly easy to do.

Or just stick with the Victron Connect app on your phone and get a dongle to change things on your laptop. That will do everything you need.
 

Butcher

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Joined
Nov 14, 2021
Messages
88
The great thing is that there is no wrong way.

One thing that should be looked at with a critical eye, is all the options. Weigh them out and figure out what works for you. Don't trust anyone that says 'This is the best way'. The best way is the one that was researched and thought about, looking at the positive and the negative sides. Building a project with one manufacturer may mean that everything works well together, but it also may mean that their software/firmware is limiting to your needs. Choosing different manufacturers may get you everything you want, but never get it to work in harmony.

In the end, when the project is completed, wishing you did it another way just ruins the hard work in the project. By discounting any method without research is just eliminating options.

I get that Victron and Battleborn are big names and cost big dollars but I would argue that they are not the best way to spend your money. Having a product that works well means you can demand top dollar. Where does those extra dollars go? Check out the CEO's house. You'll know real quick who's more important.

Plus the fact, for me, it's fun looking at what is out there and what people are doing. It's amazing the creativity that is being posted. Critiquing everyone's project and picking out what works best for you.
 

Scycle

New Member
Joined
Feb 13, 2022
Messages
42
I am also starting my 5th wheel system which is 50A, and I am just learning and thoroughly confused because I can't go all-in at this point but would like to boondock as much as possible, don't know about full time yet.

So where to start, I need a new battery so a couple lithiums are on my mind then it goes crazy from there considering everything else that's needed and the Multiplus sound simple. From what I've seen that all the parts needed to create the system may add up to the cost of the Victron if you include a decent inverter charger, transfer switch, and other components. It makes it easy to do the split phase as well although I've seen inverter chargers that do that on 12v now as well but cost with $500 of the victron alone.

If I could just change the batteries to lithium would be a nice start because that will cost enough, and I thought a couple solar panels used portable to charge batteries for now, then need a charge controller and so on and so on.

So I guess I'm looking for suggestions where to stop if I want to change batteries and charge them with solar and possibly expand?
 

Helitech

New Member
Joined
Feb 14, 2022
Messages
8
Like you, I have just started down the same road. We are looking at being able to dry camp for a week or so at a time. My Cardinal already had an inverter for fridge, I added 2000 watt inverter/charger from Xantrex, have 3 100 ah Rebel Lifepo4 batteries coming soon. Haven't installed solar yet, but I have all the wiring in place and the PV breaker installed 20220316_190538.jpg20220313_163124.jpg
 

Scycle

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Feb 13, 2022
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Helitech.
I've seen people use the toggle type of circuit breaker for the PV as you did and others use the other type below, as long as they're sized correct, would either work? I was going to start with 2 100ah brand undetermined, but I don't have anything yet, except a monitor. I see 2 Lynx distribution boxes, but do you need 2,I was thinking about getting the Power-in version then add the hardware for the fuses. I also see what looks like an auto transfer switch, so is that for the new inverter? Is the Cardinal 30 or 50A?
 

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Helitech

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Feb 14, 2022
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Helitech.
I've seen people use the toggle type of circuit breaker for the PV as you did and others use the other type below, as long as they're sized correct, would either work? I was going to start with 2 100ah brand undetermined, but I don't have anything yet, except a monitor. I see 2 Lynx distribution boxes, but do you need 2,I was thinking about getting the Power-in version then add the hardware for the fuses. I also see what looks like an auto transfer switch, so is that for the new inverter? Is the Cardinal 30 or 50A?
I think codes require both sides of the PV to be on a breaker, someone else will have to chime in on that. My DIN box cost $15 and the breaker was $16. I used the Lynx Power In with the fuse conversion. (Super easy to do) I currently have 2 spaces open, 1 will be for Solar and the other a Victron DC to DC charger. Transfer switch is for the Generator, I have an LP Onan 5500. The 2000 Watt Xantrex inverter/charger (Freedom XC Pro) has it own transfer relay. I installed a 30 amp breaker in my panel and ran 10-2 wire to the inverter, the 10-2 out of it and back to a 2 breaker sub panel. The circuits for a large number of my outlets are then connected to the 2 15 amp breakers just like they were in the original breaker box. My Cardinal is a 50 amp. If I had more room (No generator) I would have gone with the Multiplus II.
 

Paul_R

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May 7, 2021
Messages
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Location
Northern California
I think codes require both sides of the PV to be on a breaker, someone else will have to chime in on that. My DIN box cost $15 and the breaker was $16. I used the Lynx Power In with the fuse conversion. (Super easy to do) I currently have 2 spaces open, 1 will be for Solar and the other a Victron DC to DC charger. Transfer switch is for the Generator, I have an LP Onan 5500. The 2000 Watt Xantrex inverter/charger (Freedom XC Pro) has it own transfer relay. I installed a 30 amp breaker in my panel and ran 10-2 wire to the inverter, the 10-2 out of it and back to a 2 breaker sub panel. The circuits for a large number of my outlets are then connected to the 2 15 amp breakers just like they were in the original breaker box. My Cardinal is a 50 amp. If I had more room (No generator) I would have gone with the Multiplus II.
Building codes don't apply to trailers, RV's, ect. But having a breaker on both sides is always a good idea if for no other reason than ease of isolation.
 

Scycle

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Feb 13, 2022
Messages
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Like you, I have just started down the same road. We are looking at being able to dry camp for a week or so at a time. My Cardinal already had an inverter for fridge, I added 2000 watt inverter/charger from Xantrex, have 3 100 ah Rebel Lifepo4 batteries coming soon. Haven't installed solar yet, but I have all the wiring in place and the PV breaker installed View attachment 87768View attachment 87771
I might do as far as the batteries, lynx power-in w/fuses so I'll have the catastrophic fuse and disconnect switch, what did you use? Looks like ANL fuse and maybe 4/0? It's tough to size components without the rest of the system but eventually I'd like to start with my 2 100ah, maybe 400w solar, 2000w inverter. Most system diagrams I see (even small ones) have a 400A fuse at the batteries but not sure what's in the lynx.
 

Helitech

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Feb 14, 2022
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I'm not going to be pulling huge loads, so I went with 2/0 cables and a 400 amp ANL fuse on a 750 amp rated fuse holder. I think a T fuse may be better though. In the power in, my fuses start at 60 amp and up to a 250 amp.
 

Scycle

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Joined
Feb 13, 2022
Messages
42
This was a concern of mine when I first started my transition to LiFePO4 and solar. I had two inverters (one for residential fridge, one for the rest going through a sub panel), a converter/charger and two solar charge controllers. This turned out to be too complex. But it had lots of redundancy.

View attachment 79493


I grew weary of trying to remember how all of this worked and there is no chance my wife could operate this system, so I installed the MPII and that eliminated all of the complexity. Sure, I only have one inverter and the charger is now part of the inverter, but now the system is plug and play. It just works. I retained the dual SCCs because I am going to add more panels. I think this simpler system is more reliable than the redundant system. And I get a cool display in the camper.

View attachment 79495
Very nice diagram! This looks very close to what I envision except I will start about half this size and possible expansion. Wondering if this sounds reasonable: 2 100ah lithium, 2 100w panels portable for now, multiplus II (like simplicity, both lines back to rig panel, doesn't seem $$more than separate pieces), lynx power-in, 1 solar CC, & no Cerbo, display,etc? Questions: Would I be extremely oversized using your fuse and cable specs? Could the 50A breaker before the MP II be the Blue Sea din box or their breaker with the pushbutton/lever (not sure of technical name)? Is there a direct way to power the DC side of the rig panel? I see the DC/DC charger, but from what I gather from reading posts is that I don't need that with my TV ('21 F350 6.7) unless I want to fully charge the batteries-what is your TV?
 

HRTKD

Boondocker
Joined
Apr 24, 2020
Messages
7,688
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Somewhere South of Denver
I see the DC/DC charger, but from what I gather from reading posts is that I don't need that with my TV ('21 F350 6.7) unless I want to fully charge the batteries-what is your TV?

The purpose of adding a DC-DC charger is:
1. Provide a proper LiFePO4 charge profile
2. Don't overtax the tow vehicle's wiring and alternator.

Your 7-pin 12 volt circuit is limited to 30 amps (fuse and relay). A LiFePO4 battery has the potential to draw far more than that.
 

Paul_R

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May 7, 2021
Messages
101
Location
Northern California
The purpose of adding a DC-DC charger is:
1. Provide a proper LiFePO4 charge profile
2. Don't overtax the tow vehicle's wiring and alternator.

Your 7-pin 12 volt circuit is limited to 30 amps (fuse and relay). A LiFePO4 battery has the potential to draw far more than that.
That 30 amp limit doesn't address an even more important concern - losses. The voltage your batteries will see after traveling down 40+ feet from your alternator on 10/12 gauge wire will be worse than useless. You need a dedicated circuit with a minimum of 4 gauge wire.
 

corn18

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Sep 9, 2021
Messages
475
That 30 amp limit doesn't address an even more important concern - losses. The voltage your batteries will see after traveling down 40+ feet from your alternator on 10/12 gauge wire will be worse than useless. You need a dedicated circuit with a minimum of 4 gauge wire.
You don't need a dedicated circuit. I use a Victron 12/18 smart charger. My 10ga wire to the 7 pin and 30 A fuse on the tow vehicle are more than adequate to feed the 22-24V that the Victron needs to maintain a steady 14.2V @ 18A. And 18A is plenty while towing. It easily runs the residential fridge with some left over. The 1200W of solar on the roof takes care of charging.
 
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