Solar Neophyte with new 5th wheel - Upgrade Solar

[RoadTurtle]

2022 Arctic Fox 27-5L, 50a service
Zamp factory 30a controller
2 port cap on roof
one 45w panel & one 170 panel
Rest of planned configuration upgrade below the solar questions

Looking to put on another 170 panel and had a heart attack at Zamp's cost of $599. Led me to HQST 190w panel. Zamp said i have to install a 3 port cap... which had me thinking of pitching the 45w and adding a 2nd 190w panel, but this exceeds the Zamp controller's stated capacity of 510w by 40w. I think I finally understand the wiring and connector issue mixing other brands with Zamp.
Questions

• Is 550w a problem for Zamp's 30a controller (summer usage in midwest, winter out west and FL)?
• Do I have to replace the 2 port with 3 port?

Rest of the system current and immediate upgrade plans

• 2 GC2 batteries --> 2 Lithium 100a batteries (this is almost as confusing as the panels trying to identify which brand)
• No inverter --> 2200w inverter, which would plug into the 50a generator input I installed on the front, which is wired to generator ready system
• 2500w inverter generator, which is large enough to run front 13.5k AC if needed if most other loads are shed.
• Add panel breaker for on board charger, separating charger from integrated inverter.

I have no idea how far this will go, this is my first foray into solar, most of our boon docking has been a night or two, but likely to go longer in the future. Book has been sent to my home, so it will be a little over a week before I return home.

 

[MisterSandals]

I would seriously consider getting a better SCC than the Zamp, which is PWM and only 30A.

If you got an MPPT, you could get big cheap panels to fill your rooftop. Look on craigslist in your area for panels. If you post your city or zip code, maybe someone will point you to deals on panels in your area.

With 2x 100Ah lithium batteries, that's 2560Wh

Charging completely in a solar 5h day (YMMV), that would require just over 500W of solar

550W solar / 12.8V = 43A max charging

I'd look at putting something like 4x 300W panels on top and do it right the first time.
Configure as 2S2P and get something like a Victron 100/50 or 150/70 (all depends on what panels you get and their Voc)

 

[RoadTurtle]

I'll have a tough time getting passed WAF to completely rip out a new system to install a different new system, and until we know more about our usage...

When Zamp calculates 515watt max for their 30 system, is that for 30a output?

 

[MisterSandals]

I'll have a tough time getting passed WAF to completely rip out a new system to install a different new system, and until we know more about our usage...

When Zamp calculates 515watt max for their 30 system, is that for 30a output?

You could put in a separate charge controller if you are not comfortable/ready/prohibited swapping out your Zamp. Put a couple big panels up and add a second SCC. I'd make it big enough to handle 4 big panels (minimum). Other than space and wiring clutter there is really not reason to remove the Zamp.

Overpaneling is fairly common (putting more watts into an SCC than it can use) for charging earlier in the day, later in the evening and low light days. This is more helpful with an MPPT SCC where the array will have a much higher voltage than the minimum required to charge (roughly 5V higher than the battery voltage).

The 515W max, is based on what it can use, though i cannot reconcile the numbers...
515W / 14V charging = 37A

 

[Browneye]

Good advice here already...

Bear in mind an AC unit will pull 900 to 1599 watts, so your two batteries might only run it for an hour and a half or so. RV AC is notoriously inefficient and considered an energy hog. I run the genset for AC. And even then it's only good for 20-25 degree drop. If it's super hot we don't go, or we leave/move.

A 2kW inverter can pull over 200A on your batteries - takes big cables and fuses, and drains them very quickly. Consider two 200A ones with at least a 120-150A bms output capacity if you're going to run a giant inverter. Will things the Chin or AmpereTime ones are okay - a step up would be SOK. Or build your own. After a ton of research I did the latter. Well worth it.

 

[RoadTurtle]

IF AC is needed, I'll run the generator, and depending on how things go, may parallel a 2nd generator.

Looked at 200a batteries, and then I'm getting into completely reconfiguring the battery box, or moving them elsewhere. The two sliding battery trays can take the group 27(?) batteries as is, and not enough room to add two 200a.

With my old travel trailer, I could go two nights on 2 GC2 batteries with a minimum amount of charging off the 7 pin while driving.

But we are heading into a different type of camping and travel, as it will no longer be about the destination, but instead the journey as retirement is finally coming!

 

[Browneye]

Awesome! Me too...and why we made all the upgrades.
Our motorhome is 17 years old, we've gotten by with a pair of golf-cart batts for all this time, replaced them twice. Lighting and TV converted to LED, the biggest drain is the forced air furnace - it pulls about 12A running. Everything else is pretty low draw. Most of our camping has been off grid over all these years. We know our usage is about 100A per day.

It all started with adding an inverter for wife's electronics, she works remote. And for charging eBikes. We got tired of plugging in those silly cigar-lighter inverters that never seemed to have enough juice. So I bought a Xantrex 600W inverter and then it all started. LOL

Solar upgrade, 600W with two controllers. The the GC2's were getting pretty old and one cell was starting to sag, so I contemplated replacing them and then got talked into upgrading to lifepo4. Then I got talked into building a battery with prismatic cells. Then upgraded all the charging sources, and a couple of grand later we are our own power generating station. LOL

Lifepo should really live inside - they are not weather proof and prefer a climatized environment. And their charge profile is considerably different than lead acid batteries, and really should not be connected with lead acid batteries nor a vehicle alternator.

The best bet is to do an energy audit and figure out what your usage actually is, and then build a system to accommodate those needs.
For us, the 230Ah lifepo battery was twice the usable we had, at half the weight and size. I moved the house batteries out of the as-built battery box and into the main living area under the settee. We still use LPG for heat, fridge, and water heater, and the genset for AC.

Multiple batteries have the advantage of spreading current draw over several power sources and BMS's. The disadvantage is all the connecting cables and terminals, which are the key failure point in all of these systems.

Lots of good info here and lots of help. Flesh out your project needs and ask questions.

 

[RoadTurtle]

Browneye,

I really appreciate all the comments here, and maybe I do need lots more batteries and solar, but my primary usage has been charging laptop computers, and watching TV at night. I have a little 300w invertor I used to use in the travel trailer, but would like to have 120V throughout the whole trailer, which is why I'll use the generator inlet off for the 2200w inverter. Side usage, running the kurig coffee maker for what, 90 seconds? Right this second, on shore power, I'm using 2a on leg one, and 11a on leg two, and the front AC is running. Neither the fridge nor water heater are currently pulling any 120v power. I'm on my work laptop with a second LED screen, wife is on her laptop. Also, the 12V modem and 12V router are also running, along with 12v antenna booster. I'm not sure what all is wired into leg two, but that AC typically uses 11a. Just for grins, I turned on the TV and sound bar. Now I'm up to 3a on leg one, and 12a on leg two. So TV and sound bar pulled 1 or 2a additional off AC, which is pretty low.

With this trailer, the only place that would make sense for a bigger battery bank would be under the bed, but now I'm losing that storage area. With some manipulation I might be able to rotate the batteries 90° in the battery box, but it's going to require additional configuration and I still have the same issue (no matter what size battery), of being exposed to ambient temperatures.

So, not knowing how much we are going to be using campground power vs boon docking, hate to put in a huge system we may not need. It's one of the reasons I didn't get the installed generator, on my TT I can count the number of times I used the suitcase generator on one hand.

 

[BeagleHauler]

I think I may have a similar situation with my 2017 Arctic Fox 27-5L which would have the same roof space as yours, and have a single 15k air conditioner with soft start. Goal is to be able to run the air conditioner when needed (mostly on East Coast) and computer equipment (two laptops and two 32" 4k screens).

Bought two of the SOK 206 Ah batteries, Victron 3000/12 charger, Orion DC-DC (truck charger), and lots of the goodies inbetween. Doing the install myself now. Trying to determine if I can fit 1200 watts of solar up on the roof. Looks like it can be arranged with 12x 100W panels mounted sideways to two sets of (one pair each side) parallel rails running front to back. Not sure on which Victron MPPT controller would be needed or the panel configuration as of yet.

 

[BeagleHauler]

I have allocated space for a 3rd SOK battery and have a 2200W Honda portable generator as I understand even 1200W solar would not be able to charge a 618Ah battery bank in a single day.