Where should the power infrastructure really go?

[Big Rudy]

I'm changing, going from a B+ MH w/ Q4x4 conversion to a F450 4x4, super cab, flatbed, used 8.5' pop up camper. The camper is bare bones, kind of the opposite of my current rig, which I like. But I still want some upgrades.
So my question is:
I might not be a camper guy(this is my first), or not a pop top guy, or I might eventually go back to a travel trailer, or 5th wheel. I would like to take my upgrades with me, if possible.
Where should I install all the good stuff? I'm talking 300amp lithium, solar panels, controller, 2k inverter, B to B charger?
I did these improvements to my current rig, and now its all going down the road. Seems like a waste of money that I will recover very little of.
What are the thoughts out there about mounting this kind of hardware inside the truck? I will have room in the back seat area under the dog platform.
Its a flatbed and I will be installing external boxes over and under, is this a good option?
I can see this truck as my last.

I will be wanting to remove the camper from the truck and still be able to use it at times, independently from the truck. Can I leave the bare bones set up the way it is, and make a parallel power station on the truck?
The camper does not have much room to mount this stuff, and internal storage is limited, so I don't see anything more than a few solar panels on the roof.

Can I have it all, and take it with me next time around?

Would like all input, links to builds, give me what you got!
Thanks

 

[john61ct]

Everything but the panels, yes put them under your flatbed.

Beware of theft of course.

Use high-VOC rated panels, 40+ so you get lower voltage drop over distance.

Biggest wattage per panel you can fit, so smallest number of panels.

Victron SmartSolar MPPT sized per panel is optimal.

 

[4000lbsOfGoat]

If you've got the space to fit it all in boxes under the flatbed then that seems like a great option. I would, however, recommend against hard mounting the solar panels if you expect to be dependent on them for any length of time (i.e. if you'll be stationary and off-grid for more than 1-2 days at a time). You'll want to keep the rig in the shade as much as possible but be able to put the panels in the sun - and they'll need to be moved at least a few times a day if you want them to be really effective.

 

[4000lbsOfGoat]

Victron SmartSolar MPPT sized per panel is optimal.

Are you saying separate controllers for each panel? I don't think that is optimal since each controller needs to gauge the state of charge independently while the other panels (which it is not aware of) are also pushing power into the battery. I currently have 2 portable panels, each with their own controllers, and one of them always seems to get "confused" and thinks the batteries are full while the other continues to read the batteries as "not full" and keeps pushing amps for hours after the other has stopped...This week I am having a single controller installed in the camper that I can run both panels through - better to have a single controller evaluating the state of charge and adjusting accordingly.

 

[NatersXJ6]

If you see any water crossing in your future you probably want to make sure those under bed boxes are really well sealed.

 

[john61ct]

Nope, common old wives tale that.

The key is the MPPT SC controlling the panel voltage to optimise the power extraction.

There is no "confusion" with multiple charge sources going into a bank, sure better if they use the same profiles

but IRL it all works out fine in the end.

 

[4000lbsOfGoat]

Well, In my real life, managing my batteries for the last 5 weeks on the road, monitoring charge controllers all day to see how they are behaving - one of them *always* shuts off prematurely (the smaller panel of the pair). If running both panels through a single controller doesn't get me better uptake then I'll come back here and eat my words

 

[4000lbsOfGoat]

It cant hurt to try...
From prior messages, ”the smaller panel of the pair” appears you have two portable arrays of different electrical properties ?
Perhaps study what happens if connecting arrays with different properties to a single controller.

That's the plan! I've actually got 3 separate panels but 2 (90W each) are paired in a single "briefcase" unit (what a misnomer! no one would want to carry that "briefcase" around ) and run through a single controller. The third is 100W and has it's own controller. Both outputs are connected to a single Zamp input using a wye connector. The 100W is the one that always shuts off prematurely. The new setup will have the raw output of all the panels run to the Zamp input connected to a single 400W controller. I expect better performance from a single controller reading state of charge and managing one lump of raw input.

 

[4000lbsOfGoat]

If you know something I don't know and that isn't going to work, please tell me now! The new charger is getting installed this week, lol!

 

[Big Rudy]

Mounting in the external boxes does make me nervous, mostly the moisture issue, theft not so much, but still an issue.

Someone must have opinions about mounting this in the back seat area of the cab. Is this crazy thinking?

 

[Big Rudy]

I'm meeting with a power systems guru this week to decide the layout. Not much feedback from these parts?????

 

[Rando]

I would just mount it all inside the camper. You want all the chargers (solar, B2B, shore power if you have it) to be close to the battery. If you have a lithium battery and plan on camping in cold weather, you want the battery to be inside your heated/insulated living space to stay warm. It is also nice to have relatively easy access to the components for futzing and adjustments.

One option to make it more portable is to mount all the parts, and the interconnecting wiring to a single panel (plywood or something fancier) and then mount that to the wall of the camper inside the electrical cabinet. That way when you want to pull the good bits out, you just unscrew the panel, disconnect a few wires, an you are good to go.

 

[Rando]

If you know something I don't know and that isn't going to work, please tell me now! The new charger is getting installed this week, lol!

Your solar charge controllers aren't really sensing the state of charge of your battery, only the voltage of the battery and maybe the acceptance (or tail) current right at the end of the charge. The chargers will stay in bulk mode until they see the battery voltage rise to the absorb voltage, then they will switch to absorb and hold that voltage either for a predetermined time (most likely), or until the acceptance current drops below some value (less likely), at which point they switch to float. It really makes no difference whether you have two controllers each measuring the battery voltage independently, or one controller measuring it. The only thing that might change a little bit is if your controllers use acceptance current to terminate absorb and switch to float as the controller can't see the current from the other controller. However, at that point the battery is within a percent or two of fully charged, so it doesn't really matter.

With MPPT and dissimilar panels you will do better with one controller per panel as each controller can find the max power point for each panel, as opposed to an 'average' max power point for the combination, which is not ideal for either panel. For PWM it doesn't really matter.

 

[4000lbsOfGoat]

Your solar charge controllers aren't really sensing the state of charge of your battery, only the voltage of the battery and maybe the acceptance (or tail) current right at the end of the charge. The chargers will stay in bulk mode until they see the battery voltage rise to the absorb voltage, then they will switch to absorb and hold that voltage either for a predetermined time (most likely), or until the acceptance current drops below some value (less likely), at which point they switch to float. It really makes no difference whether you have two controllers each measuring the battery voltage independently, or one controller measuring it. The only thing that might change a little bit is if your controllers use acceptance current to terminate absorb and switch to float as the controller can't see the current from the other controller. However, at that point the battery is within a percent or two of fully charged, so it doesn't really matter.

With MPPT and dissimilar panels you will do better with one controller per panel as each controller can find the max power point for each panel, as opposed to an 'average' max power point for the combination, which is not ideal for either panel. For PWM it doesn't really matter.

After a week and a half on the road with it now I'm quite pleased with the single controller running all the panels!

I think that the issue with my previous dual-controller setup was that, as you said above, they were both looking for the battery to hit absorb voltage but the output of the one panel caused the other panel to "see" absorb voltage when the battery wasn't really there - thus it would switch to float prematurely.

Thanks for the feedback!