Solar Newbie building LiFePO4 batteries for full time boondocking

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RobinTH

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Failing health and therefore failing finances are forcing me into full time RV boondocking and of course everything will be DIY. I plan to build 4, 12volt batteries using EVE LF280k cells (1120 ahrs), in parallel feeding a busbar feeding a 4000 watt inverter. The roof will be covered in solar panels and next year I will build a wind turbine. I'm guessing muliple solar/ wind controllers and probably a DC to DC charger to top up the batteries during travel. Any thought you may have on these various topics would be gladly received as college electronics was 46 years ago. Thanks
 
all sounds good.

you will not have any air conditioning boondocking unless you have a generator.

propane is something to have plenty of while boondocking too. some of your power needs can be switched to propane as needed and you will need propane for heating.

wind generation is a great add on as that can provide power 24/7. there are some rv friendly wind turbines out there. you could consider cutting back initially on your solar build to free up resources for wind generation.

when boondocking, its typical to live a life style based on your power availability day to day.

lastly, your location is important for heating. heating requirements in cold weather will be large and can become impossible in unfavorable circumstances.
 
Thank you for your reply Henry. I would love to have the wind turbine this coming winter as I doubt I will get very far west where the good sun is, but I don't want a Chinese piece of junk and I can't afford a high quality unit, so it will be a scratch built affair using the Hugh Piggott design. I doubt I have the time to do it this year with all the other work I have ahead of me. I would love to hear from someone that has done something similar themselves, and could offer technical advice. Thanks for time, Robin
 
For a bit more than the price of the EVE LF280k cells you can get the same capacity in pre-assembled 100 a/h lithium batteries (prices start around $300 on Amazon). Check out Will Prowse's videos on YouTube - he's a self taught lithium and solar guru and has torn apart many of the batteries and reported on how they stack up. Don't forget you'll need a BMS for each set of the EVE cells which will raise their price.

The biggest thing with LiFeP04 batteries is you must not let them try to charge if their internal temperature is below freezing. They'll deliver power to well below 0 F but will be permanently damaged if you try to charge them when they're too cold. Some have internal heaters or a BMS that will refuse to accept charging current if it's too cold but many don't.

If you have the roof space, the best bang for the buck are surplus panels removed from fixed installations when their tax credits ran out. You can get them for practically nothing. Santan Solar was the first to market these, there are now others. See if you can find a seller close to home as shipping can be expensive. I was able to fit 540 watts of these panels on top of my 29 ft. Safari motorhome and have room for more.

An MPPT controller will interface these to a 12 volt system. Use an inexpensive one like the Epever and you have the start of a very capable system for not much money.
 
I did a similar project with 1200 amp/hours of Lithium.

Lou, who posted above helped me with mine.

You might get some ideas from this link.

New Project, Solar for Class C

I have been doing almost nothing for the last 7 months so I am going to get off my butt and start a new project, I am going to put as large of a solar installation as I can on the Class C Chateau. I am limited by usable roof space but I think I can put 8 (200 watt panels), on the roof for...
www.rvforum.net
 
Thanks for replying Lou. I have been viewing Will's videos and will continue to glean what knowledge I can from him. I like the idea of not having to build the batteries but that won't work for me. I looked at the low end batteries such as you mentioned, but I don't have the space for 11 of them to get the same 1120 amphrs I will get from 4 of the much smaller batteries I will build. Then again I will end up with 4 high quality batteries for the price of 11 low end ones. Good point about the cold temperature charging issue. I plan to spend the winter just above the Mexico border so hopefully that won't be an issue. I plan to build a chamber behind the propane tanks to house batteries and all electronics, so I could add a thermistaticlly controlled heater in that box if necessary. I do plan vents on the bottom and an exhaust fan on a thermistat for the hotter weather, but I hope to avoid most of that by heading north as the temperature rises in the spring. I'll check out the charge controllers you mentioned. Do you have personal experience with that brand? I checked into the used panels as you mentioned, but as you thought, shipping kills that idea for me, as new panels, sourced locally, is almost the same as used. Thanks again for your thoughts. Thanks, Robin
 
HueyPilotVN said:
I did a similar project with 1200 amp/hours of Lithium.

Lou, who posted above helped me with mine.

You might get some ideas from this link.

New Project, Solar for Class C

I have been doing almost nothing for the last 7 months so I am going to get off my butt and start a new project, I am going to put as large of a solar installation as I can on the Class C Chateau. I am limited by usable roof space but I think I can put 8 (200 watt panels), on the roof for...
www.rvforum.net
Click to expand...
Thank you Bill for that link. I will check it out. Thanks, Robin
 
Yes, I have the 40 amp Epever and it works fine. For another $20 you can get a remote display panel that duplicates what's on the front of the controller.

My system is the 3 solar panels, Epever MPPT charge controller and (2) Lion Safari UT1300 105 a/h lithium batteries. I got the Lion Safari batteries about 2 years ago when Costco had a special ($750 each) and they have an unlimited lifetime warranty. Guaranteed to have 80% capacity remaining after 10 years or free replacement.
 
Thanks Lou, I will look into that controller. I haven't worked out the panels completely yet so I don't have wattage figures so not sure what I will need at present. I never thought of Costco. They have a 2 pack of your battery for $1400. Thanks, Robin
 
Designing for it though requires a boatload of panels to feed it. No matter how big a battery bucket you have, eventually it needs to be refilled. Additionally, baking in the sun so your panels are illuminated is a vicious circle so even if possible, seems a plan with diminishing return.

Mark B.
Albuquerque, NM
 
Frank B said:
You sure about that? With 1120 ah of Lithium storage and 4Kw inverter?

What was not possible or not practical years ago is becoming doable these days if you design for it. A quick Google shows lots of ways to do it.
Click to expand...

storage is getting better. lots of variables. unlikely you will have any sustainability without back up power but if you would like to create a set of realistic circumstances, this forum has several great solar friendly members that can dive into it.
 
Mark & Henry:

Admittedly, the usage scenario plays into this. OP is a fellow Canadian, so I was looking at solutions for a snowbird, like myself. Trying to keep cool in an RV in Quartzsite during the summer is somewhat futile regardless of what you have. However, if A/C is only needed during peak hours during the day, it may not be an impossible task to run it off solar while boondocking. With lithium batteries, we could probably do it.

I'm trying to post this from my phone, which I don't usually use. The link I gave to the thread above is a link to the search I did rather than the actual thread of our install. Just touch the top of the link and it will take you to the actual thread.
 
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Frank B said:
You sure about that? With 1120 ah of Lithium storage and 4Kw inverter?

What was not possible or not practical years ago is becoming doable these days if you design for it. A quick Google shows lots of ways to do it.
Click to expand...
It can be done, but the battery bank will have to be huge and the solar panel array to recharge them will require a trailer to tow it, along with every square inch of the RV covered in them. Battery-powered A/C is only feasible in a stationary residence with an entire building dedicated to the off-grid infrastructure.
 
Tulecreeper said:
It can be done, but the battery bank will have to be huge and the solar panel array to recharge them will require a trailer to tow it, along with every square inch of the RV covered in them. Battery-powered A/C is only feasible in a stationary residence with an entire building dedicated to the off-grid infrastru
Click to expand...

I suggest not. Like I said, do a quick Google search, and you will see that a number of people are already doing this. Will it work in Quartzsite in the blazing sun in the middle of summer? No. But what system for an RV will work in Quartzsite in the blazing sun in the middle of summer?

It depends on what you are looking for and what your expectations are. Don't discount the possibility because it won't meet every scenario.
 
Thanks to all who have commented. I don't know how we got down the AC road, that won't be much of a concern for me. I will be heading south from Nova scotia in the Fall, spending the Winter in the southern states, probably not west of Texas, heading north as temperatures rise. As soon as I calculate the solar I can fit on the roof, I'll post a proposed schematic for people to critique. Thank you everyone!
 
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