Easiest Budget Setup for Van Conversion?

[reecetas7196]

Hello!

I am new to all this and am going to purchase a couple solar panels, used, by SunPower. The model is SPR-220-BLK-U. They are monocrystalline cells.

I wanted to know what would be the most budget friendly and efficient setup for these.

What kind of MPPT charge controller?

If I were to use 4 of these, https://offerup.com/item/detail/1247726770, for a 12v LifePo4 battery, what else would I need?

What size inverter? I think a 2000w should be fine?

Main things running off of it would be LED can lights, weboost, vent fan, charging for two laptops and iphones, maybe dometic fridge eventually.

Any help would be awesome!! Thanks!!

 

[John Frum]

The size of the inverter is determined by the loads you plan to run.
I posit that you should design your system based on requirements.
When you design based on requirements the pv panels are near the last thing to consider.
How much momentary power do you need as measured in watts and how much power over time do you need as measured in watt hours?

See my signature for a link to a tool to help with your audit.

 

[John Frum]

@reecetas7196 your link doesn't work.

 

[Browneye]

You understand a 2000w inverter can pull about 200 amps 12V? So if you use your full capacity your 200A pack may only be good for an hour.
And you're going to start out with building your own battery pack?
Looks like a good deal on the cells...but that's just the foundation of a big project with a steep learning curve. BTDT, right in the middle of it.

Those panels are grid-tie type as opposed to 12V mobile type. They'll work, but you'll need a charge controller that can accommodate them. Pretty high voltage on those - about twice that of 12V type.

I think most here would encourage you to view the video series from Will's YT channel - may give you a better start and help you formalize where you're going with it all. Sounds like some kind of RV, first step is an energy analysis - determine what your needs are in amp hours and then address how you'll supply those.

 

[Browneye]

@reecetas7196 your link doesn't work.

Try this for panel specs: http://www.posharp.com/spr-220-blk-u-solar-panel-from-sunpower_p602011405d.aspx

The other link is an offer-up listing for 4 202AH lifepo cells. It worked for me.

 

[John Frum]

Try this for panel specs: http://www.posharp.com/spr-220-blk-u-solar-panel-from-sunpower_p602011405d.aspx

The other link is an offer-up listing for 4 202AH lifepo cells. It worked for me.

I think its region locked.

 

[Browneye]

Could be. It's a listing in Temecula CA:

Description​

Fire sale needing to get Eric of them to make room for more incoming cells I’m dropping the price to $85 each. New 202Ah lithium iron phosphate cells. 3.2 volt nominal Perfect for solar project or RV. Shipping is available


I assume 'eric' is an auto-correct for 'rid of' or some such.
Maybe a cell reseller, eh? $85 is a good buy. I just gave $108 for brand new Eve 230Ah cells from Amy Zheng. They're due in from China to their Houston warehouse within the next couple of weeks.

I've spend countless hours so far pouring over the content from Overkill Solar BMS, their install instructions is 79 pages. And my amazon cart has some 27 items in it, from bench power source to crimp tools and terminals, and on ad infinitem. LOL Building a lifepo pack is no small undertaking. Fun, but challenging for sure, and I'm a computer tech consultant.

 

[reecetas7196]

@smoothJoey Thanks for the feedback! I'll check out your link.

@Browneye Thanks for all the info. I'm definitely newb here. We're converting a 2002 Ford e150 conversion van. I didn't purchase the solar panels, but am thinking about it, but after your feedback, I believe I may change course. I'm just looking to piece together an affordable solar system for the van. Probably not the best route to take, but I've been known to not always take the easiest route. I can a be a "work harder not smarter" kind of guy sometimes lol

Anyway, with four of those lifepo cells, do you have recommendations for a BMS and solar panels? I have limited roof space. I saw those were 220ah so I thought they'd be a good idea. I'm in the IT field, but don't know much about electricity lol \_(*-*)_/

 

[Browneye]

Haha, yeah, I dropped out of electronics and electrical at the community college when I was 19. Even as a math-wizz when it got all into the math part of it my eyes glazed over. Here I am still doing this stuff.

Will has some good vids and how-to's on setting up solar on a van or RV. Another guy worth watching is

https://www.youtube.com/c/EXPLORISTlife

This guy is really good too, easy to understand, good demonstration of techniques, very creative:

https://www.youtube.com/c/FreelyRoaming

If you watch for Home Depot sale on their Nature Power brand panels they are a real bargain - I got two 215w mono panels from them recently for $154 each. I went with Epever Tracer Xtra 30a controller and just thrilled with the way everything turned out. I haven't gotten to use it much yet, but good results testing it out. Now I'm setting out to build a 230A lifepo pack from raw cells. Check out my recent thread for some ideas.

Residential/commercial grid-tie panels can work out, but they're large and heavy, and higher voltage than 12v style panels. Setting them up for 12 volt power is easier with the 12v panels.

The first thing you need to do is make an assessment of what your projected power needs will be and then build a system to supply that. This part was easy for me because we already had a fifteen year history of use, a lot of dry-camping, and all of the other systems in place for cooking, hot water, air conditioning, and etc. The 12V side of it all is just one part of it.

A couple of months ago I decided to get a pure sine wave inverter for the wife so she could plug in her laptop, charge phones, watch TV, etc. I got a Xantrex 600w at a good price, and installed 3 receptacles in the coach, one at the front near the cab, one outside on the radio box, and one in the master stateroom. This worked out really well, but got me started on this popular quest for more power and off-grid charging. So then came the extra panels to supplant our 'solar suitcase', then the realization came that the two golf cart batteries were nearing their end of life so time to think about replacing them or going for an upgrade. This forum helped me conceptualize what it might take to build a pack, as the option for Battleborn batteries just isn't in my realm of reality.

My neighbor did a van conversion type build and has 6 of those 100A batteries - some five thousand dollars worth!! He has 1600w of solar and runs everything - no generator. But he has specialty fridge, heat, AC, and water heater systems to make everything more compatible to be fully electric.

Lots of friendly help here!

 

[MisterSandals]

I'm just looking to piece together an affordable solar system for the van. Probably not the best route to take, but I've been known to not always take the easiest route

You’ve fallen quite a way from the title of your thread “Best Budget Setup”.
Maybe should be “easiest budget setup”.

Great advice from @smoothJoey in post #2.
Doing an audit is MUCH more that arriving at a number. You will learn more during this simple step than any other. And what you learn will be useful any time you think about using your system.

 

[reecetas7196]

You’ve fallen quite a way from the title of your thread “Best Budget Setup”.
Maybe should be “easiest budget setup”.

Great advice from @smoothJoey in post #2.
Doing an audit is MUCH more that arriving at a number. You will learn more during this simple step than any other. And what you learn will be useful any time you think about using your system.

Updated the thread title

 

[John Frum]

There is budget and then their is budget.
An inverter/charger is the easiest and very close in price to a discrete inverter, ac charger and automatic transfer switch.

 

[reecetas7196]

What about two of these panels:

https://www.renogy.com/template/files/Specifications/RNG-280D.pdf

4 of these at about 112ah per (I believe):

https://www.alpha.com/download/outside_plant_power/alphacell_batteries/xtv/alphacellXTV_datasheet.pdf

And whatever charge controller you all may suggest and all the other stuff I may need as far as an inverter, fuses, relay for alternator to charge, shorepower integration, etc...

Also, estimated my average total daily amp draw to be about 174ah

 

[MisterSandals]

What about two of these panels:

You’re building this backwards so any solar panel is equally a good or bad guess.

Have you guessed what battery (type, size, voltage) you expect to have?

With that, figuring out solar and SCC is possible, easy actually.

 

[MisterSandals]

for a 12v LifePo4 battery, what else would I need?

What size inverter? I think a 2000w should be fine?

So I reread the OP and gleaned more info.

If you are considering a 2000W inverter, that should be battery with 200Ah, capacity minimum (12.8V x200Ah = 2560Wh for ~1.25h runtime less .85 efficiency, so maybe 1hr).

To recharge this in a standard 5h solar day, that would need:
2560Wh / 5h = 511W of solar
511W / 12.8V = 39.9A charger

 

[reecetas7196]

You’re building this backwards so any solar panel is equally a good or bad guess.

Have you guessed what battery (type, size, voltage) you expect to have?

With that, figuring out solar and SCC is possible, easy actually.

Not sure I follow? I listed the batteries I could possibly get and the panels. I'm just weighing my options here. After calculating what my average amp hours would be the initial 4cell lifepo wouldn't be enough so I went with these that I found.

Forgive my ignorance here, but again, I'm a newb. Backwards or not, I'm just looking for a little help

 

[Browneye]

What about two of these panels:

https://www.renogy.com/template/files/Specifications/RNG-280D.pdf

4 of these at about 112ah per (I believe):

https://www.alpha.com/download/outside_plant_power/alphacell_batteries/xtv/alphacellXTV_datasheet.pdf

And whatever charge controller you all may suggest and all the other stuff I may need as far as an inverter, fuses, relay for alternator to charge, shorepower integration, etc...

Also, estimated my average total daily amp draw to be about 174ah

Also hi-volt panels - 60 cell. 12V panels tend to be 32 cell as a rough standard. But two in series is do-able with an mppt charge controller. I would be looking at 40A for two.
Make sure you can fit panels that size on your roof - they're 40" wide and 65" long. If they're butted right up to each other, which is difficult to do, they're still a little wider than your roof. Notice they are 40lbs as well, a 215w 12v panel is about 25.bs. And you need to think about an attachment/racking system for them as well..

Those batteries are AGM. Which are good, but expensive for what you get. If you're building a system from parts/scratch, then lifepo4 makes a lot of sense, and if they fit your budget. They also weigh half as much, which helps in design parameters, especially for a van. Good 100a packs are $800 (Battleborn) cheap ones are $400 (amazon). Those AGM's are likely $200 each, and you can only use about half their capacity or risk serious degradation.

What @MisterSandals is trying to convey is that you need to assess what exactly you want to power up and for how long. Otherwise you don't know what capacity of anything you need. It's like jumping in your car to drive across the country with no map.

 

[MisterSandals]

After calculating what my average amp hours would be the initial 4cell lifepo wouldn't be enough so I went with these that I found.

Ok, I see the link for the LiFePO4 cells, I read that as a link to panels, sorry.
Ok, 202Ah is a good start.

What about two of these panels:

250W with 38 Voc

4 of these at about 112ah per (I believe):

Yes, the 240xtv is 112Ah (56Ah usable because only allows 50% discharge).

4 of those are marginally more capacity than 202Ah LiFePO4 cells and probably 4x the size and weight (and cost?).

≈======
So with so little to go on, my guess would be for 4x the 220W sun power panels in 2S2P configuration. The 4x LFP cells (and BMS), and a 40-60A SCC.

If you have a budget, quality or ease of use, warranty or other preference(s), we can recommend an SCC.

Let me provide the Cadillac solution (Bluetooth HIGHLY recommended):

https://www.amazon.com/dp/B073ZJ43L1

 

[reecetas7196]

Right on! Thank you for all your help and input here. I'm just brainstorming here to get an idea, but the more I read of y'all's suggestions the more I lean towards the 4x lifepo. 4x 220w panels I don't believe my roof would accommodate. I would need more along the lines of two, three at most, panels that, according to https://gpelectric.com/calculator/ , says about 500 to 570w.

 

[MisterSandals]

the lines of two, three at most, panels that, according to

3 panels gets messy with high amps if in parallel and needing to be fused. 3x in series requires an SCC that can handle 3.25x the Voc ( Victron 150/50 at nearly 2x the cost).

Shoot for 2 huge 250W+ panels or 4x smaller to Tetris fit.