Build a system for a Kimbo truck camper

[rkemether]

My son is living in his Kimbo truck camper mounted in a Toyota Tacoma. The camper came with an Eco Flow River Pro and additional battery; about 1440 watts total. There are two solar panels at around 150 watts. The Eco Flow is failing fast. He'd like to replace it with a home built system. It seems pretty straightforward, with a solar controller and two 12v 100 amp hour batteries tied into the system. However, the Kimbo has a 110 shore power connector, and the Tacoma has a 400 watt, 110 plug in the bed. He's been able to charge the EcoFlow when driving the truck, this is very convenient in the Colorado mountains. Is there a solar controller that also acts as an inverter/charger for shore power? Or perhaps some kind of automatic switch between the solar controller and shore power. This is all very new to us. I'd very much appreciate being pointed in the right direction.

 

[Rednecktek]

Sounds like a fun project, send him our way! We don't bite... hard.

A few tips right off the bat and then I'll go grab my blurb to get him pointed in the right direction:

1: Get ALL the solar panel on the roof you can, you'll need it!

2: A proper MPPT controller is a must. If it has USB ports on it, it's a FAKE mppt controller and they'll be laughing all the way to the bank.

3: Physics is pretty unforgiving so figuring out where to stick things is a must. Often times a single 200a battery will take up less space than a pair of 100ah batteries.

4: There are LOTS of brands out there that will turn solar DC into battery DC into wall outlet AC. Don't let the smurfs on here brow beat you into selling a kidney because it must be $$Victron Blue.

Ok, let me go grab my blurb, brb.

 

[Rednecktek]

Blurb time!

Well, I'll start the default answer to these questions and we can work from there. Here's you To-Do list:

1: Power audit! This will give you some important information on how big your inverter needs to be as well as how much battery capacity you'll need. There is a link in the FAQ section (I think, or someone here will post it shortly) so fill in the blanks and see what it comes up with. You'll probably need some sort of Kill-A-Watt to get accurate measurements. Are you going to be running a 12v system? 24v system? 48v system? What are the specs on your solar panels? VoC? Vmp? Being as this is a new build, throw together a wish list of what you want and estimate on the high side.

1a: Where do you live? Speccing out a system for Scotland is a LOT different numbers than Arizona due to the amount of light you actually get. Someone here can post the link to the PVwatts.com or JCR Solar Uber-Sun-Hours calculator sites to help figure out how much you'll have to work with. That will be a box in the Power Audit form.

2: Parts list: You don't need a make & model list, just a parts list to start from for reference. You'll need an inverter, a MPPT charge controller, fuses, shunt, buck converter, batteries, wire, etc. Once you have a basic list it can be fine tuned to make & models after that. If you're looking at the All-In-Ones check for correct voltage outputs (120v or 240v Split Phase for North America, 220v Single Phase for European type areas) and make sure it has enough capacity for a little bit of growth and fudge factor.

3: Budget!: Steak is great but doesn't mean anything if your wallet says hamburger. Figure out what you're able to spend now vs what you'll have to cheap out on now and upgrade later.

4: Tape measure! Figure out where you're going to stick all the stuff you'll need. A dozen 3000AH batteries sounds great until you're sleeping on the floor because there's no room left for a bed. Is there a compartment that can house all this stuff? Will the server rack batteries fit? Are you going to have to make space? Physics can be pretty unforgiving.

5: Pencil out what you think you need and throw it at us so we can tell you what you've missed (because we ALL miss stuff the first go-round ) and help figure out which parts and pieces you're going to want to get.

Well that's the thing about solar systems, there is no 1-Size-Fits-All answer. Your system will need to be designed to fit YOUR needs. When you design and built the system, it's not going to be the perfect system for me, or Will or 12vInstall or anyone else, but it Will be the right system for You and that's the goal.

As for where to get started, let me throw my standard blurb in here to help point you in the right direction. There's going to be a lot of math and research involved, but that's going to be a LOT cheaper than just buying parts off of someone's list and finding out that it doesn't do what you need.

Don't panic on the Power Audit, you'll actually be doing that a few times. When you do the first pass put in ALL the Things that you might want. AirCon? Sure. Jacuzzi? Why not. MargaritaMaster-9000? Go for it.

The second pass will be the "I Absolutely Need This To Survive" list that isn't going to have much on there.

The third pass will be the "This is what is realistic" audit that you'll use to design the rest of the system.

The Power Audit is going to tell you 3 primary things: 1: How big does your inverter need to be to power your loads? 2: How much battery bank do you need to last $N number of days with krappy weather? and 3: How much solar panel will I need to install to refill those batteries in a 4 hour day (the average usable sun hours rule-of-thumb).

Once you know what you Want and what you Need and what your budget can Afford there will be somewhere in that Venn diagram where those three things meet.

After that, THEN you can start looking at parts.

Yes, it's a long drawn out process, but it's worth it in the end. Not every house has the exact same floorplan, not every vehicle is the same make & model, and not every solar system is designed the same.

 

[rkemether]

This will be a 12v system. At this point we only need to replace the 1440 watt Eco Flow. We plan to use all the existing wiring, solar panels, bus bar, etc. Really all he needs to run is the refrigerator, LED lights, furnace fan, and charge his iPad and phone. The 1440 watt Eco Flow worked fine all winter in the Colorado mountains, but now it's capacity is much degraded. Space wise, two 100 amp hour Li batteries will fit nicely in the space, and provide a bit more capacity. The Eco Flow River Pro presumably has a built in solar controller, AC to DC step down converter to accept shore power, DC to AC inverter to provide 110v off the batteries, circuit breakers, and various 12v DC and 110v AC plugs. We need to mimic what the Eco Flow contains. Batteries, wires, and plugs is pretty simple. It's the shore power charger/converter, solar controller, and circuit breakers that we need to nail down.

 

[Dave in AZ]

This will be a 12v system. At this point we only need to replace the 1440 watt Eco Flow. We plan to use all the existing wiring, solar panels, bus bar, etc. Really all he needs to run is the refrigerator, LED lights, furnace fan, and charge his iPad and phone. The 1440 watt Eco Flow worked fine all winter in the Colorado mountains, but now it's capacity is much degraded. Space wise, two 100 amp hour Li batteries will fit nicely in the space, and provide a bit more capacity. The Eco Flow River Pro presumably has a built in solar controller, AC to DC step down converter to accept shore power, DC to AC inverter to provide 110v off the batteries, circuit breakers, and various 12v DC and 110v AC plugs. We need to mimic what the Eco Flow contains. Batteries, wires, and plugs is pretty simple. It's the shore power charger/converter, solar controller, and circuit breakers that we need to nail down.

How do you know ecoflow capacity is degraded? It shouldn't be, lithium batteries don't get degraded unless cells get out of whack, and then it's mostly fixable by proper drain, recharge, balance. What are you using to test your capacity?
Are you just relying on some % number showing on the ecoflow?
Even of its capacity IS down, you sound like on a tight budget, why would you toss it? Just buy some LFP batteries to expand its capacity and keep using ALL THE OTHER STUFF IY DOES. Inverter, ports, etc. Get a $60 LFP battery charger, plug into ecoflow to recharge your new LFPs when needed.
Plug the LFPs into the ecoflow 12v input port to kind of trickle charge it, as if it was plugged into car. Viola, expansion battery, problem solved cheap and easy.

Oh, and drain your ecoflow to zero, then recharge using a $12 KillAWatt meter to see how much it is actually taking, let it sit plugged in for days to balance. Probably fixable.

 

[HarryN]

This will be a 12v system. At this point we only need to replace the 1440 watt Eco Flow. We plan to use all the existing wiring, solar panels, bus bar, etc. Really all he needs to run is the refrigerator, LED lights, furnace fan, and charge his iPad and phone. The 1440 watt Eco Flow worked fine all winter in the Colorado mountains, but now it's capacity is much degraded. Space wise, two 100 amp hour Li batteries will fit nicely in the space, and provide a bit more capacity. The Eco Flow River Pro presumably has a built in solar controller, AC to DC step down converter to accept shore power, DC to AC inverter to provide 110v off the batteries, circuit breakers, and various 12v DC and 110v AC plugs. We need to mimic what the Eco Flow contains. Batteries, wires, and plugs is pretty simple. It's the shore power charger/converter, solar controller, and circuit breakers that we need to nail down.

That is actually a non trivial requirement, even though it is common.