diy solar

diy solar

I am always fantasizing about having a energy efficient air conditioner for van life, anyone seen any concepts in tech news or anything?

If you are talking about mc4 branch connectors.
Two for the positive and two for the negative.
Those are the typical Y connector, which is why it would take two of each. If I am not mistaken there may be some the allow three panels in one connector which would only reguire one each for negative and positive but it may depend on how close the panels are to each other for that to be physically possible.
 
Yup
If they can all reach the same place.
A multi wire branch connector will do.

Slocable T Y Branch Connector IP68 Waterproof 1000V 1500V Solid Copper Terminal in PV Solar Series or Parallel Circuits 1 Pairs (3to1 Branch) https://a.co/d/is3vMfW
 

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Thank you for the excellent suggestions for branch connectors for my three panels.

The three panels are 40.6" wide and 81.9" long. The Male and Female terminals are located in the middle about 6" from the edge and the wire is 53" - 55" long. The panels will mount side by side crosswise on the van roof which makes it a bit of a challenge to connect the outside terminals to the middle. I'm not absolutely sure that a (M/FFF and F/MMM) like this : https://www.amazon.com/dp/B08FLGCYPD/ref=twister_B0788KB8MR?_encoding=UTF8&th=1 will work. All terminals have to meet in the middle.

Q.PEAK_DUO_L-G8.2_415W.jpg
 
Might need some of these

1 Pair Black + Red 10AWG(6mm²) Solar Panel Extension Cable Wire Connector Solar Adaptor Cable with Female and Male Connectors (3 FT-2) https://a.co/d/6UFFcv4
Yes, I think those would at least move the center closer to one side or the other. Its a matter of inches, if you move left then you're short on the right and vice versa; these extensions will make up the difference on the short side. Extend one of the panels. Thanks.
 
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3 in series is too high for voltage.
Going to have to go with parallel.
If you had a 4th panel, you could go with 2S2P.
Tim, if you saw how big these panels are!; wonder if a fuse somewhere near them before they make it to the SCC would be necessary? A cut off for the panels is probably a good idea.
 
Tim, if you saw how big these panels are!; wonder if a fuse somewhere near them before they make it to the SCC would be necessary? A cut off for the panels is probably a good idea.
Anytime you parallel 3 or more strings/panels, a fuse is required on the positive of each string/panel.
And it's recommended to have a solar disconnect, near the SCC. For maintenance and emergencies.
 
Anytime you parallel 3 or more strings/panels, a fuse is required on the positive of each string/panel.
And it's recommended to have a solar disconnect, near the SCC. For maintenance and emergencies.
Tim,
I think I need a 40A fuse for each of the three panels; just not sure what type of fuse and where exactly it would go. A fuse between each solar panel and the branch connector will be on the roof in the elements. Are they supposed to be exposed and under the panels?
 
"Any time there are three or more parallel panels or strings of panels, there must be fuses or breakers on each string."
file:///C:/Users/guidecca/Downloads/Over-paneling.pdf
No mention of fusing each panel; just fuse the string? Could a fuse/breaker be located somewhere other than the top of my van? What type and size fuse/breaker do I need to buy?

I think I found the answer; just have to source the parts. https://www.windynation.com/jzv/inf/how-properly-fuse-solar-pv-system
Q.PEAK DUO L-G8.2 415W Solar Panel .jpgQ.PEAK DUO L-G8.2 415W Solar Panel .jpg
 
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A 3.1 cu ft mini fridge can be bought at Walmart for $130
Nearly the same tech needed for a mini AC

I have yet to understand why a 1000 btu miniaturized version of a 5000btu window unit has not been made?
I do believe the components are readily available?

Something about 10in wide x 12in deep x 7in tall using 500watts max startup surge and 100 watts running...on DC

All in the $500 or less price range. Millions would be sold if they were reliable
Retired auto mechanic and handyman here. When I took the A/C class at UTI when training for automotive, the standard a/c setup in a car was 50,000btu. (all that glass and not much insulation at all) Trying to do anything with 1,000btu unit is a bit too minimalist, ser. I've seen some sweet installs of mini-splits in RVs and am convinced that they are absolutely the best way to go. 38seer is just unbelieveably efficient. If you don't mind charging your battery by running the RV every several hours, you might be able to get by with a 5,000btu wall unit and inverter, along with fewer solar panels. But that seems like a kludge to me. The small mini-splits are the best of both worlds, IMO.
 
About the cheapest mini split is around $700 for a heater and an air conditioner; that would be a 9,000 BTU model. I am installing one on the bumper of my Ford E-250 van very soon. Was surprised at how much it weighs; just hope my bumper can hold it. Could probably get by with a 5,000 BTU if they made one that size. Dual purpose is comfort and to keep LiFePO4 batteries cool or warm, as the temperatures change.
 
Tim,
I think I need a 40A fuse for each of the three panels; just not sure what type of fuse and where exactly it would go. A fuse between each solar panel and the branch connector will be on the roof in the elements. Are they supposed to be exposed and under the panels?

Wrong link, those are actually blocking diodes.
This is a link for fuse holders.

 
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Three 415W panels mounted on a 2007 Ford Econoline E250. Getting ready for the mini split on the rear bumper.

Are those half-cut cells in panels?
Each diode-bypassed second would act like two panels in parallel.

How is the array wired?

The rack has vertical pieces in the corners. At some sun angles, one of those would heavily shade one or two cells, causing loss of production from that portion of the panel. Depending on array wiring, it may cut in half output of that one panel. In a series-wired array, depending on MPPT algorithm, these panels can also cause reduced production from others in the array because at some voltage the panel delivers half current not zero, and algorithm stops.

To test without waiting for a particular sun angle while electrically loaded, when powering load at any time of day, you could cover a single cell and observe how volts/amps are affected. Give it a number of minutes for any slow algorithm to respond, not just fast power-point tracking.

If shadows significantly reduce output you may want to cut those posts.
 
Hedges, these are half-cut panels, bi-facial. I planned on wiring them in parallel due to voltage being too high for series with a Epever 4215BN charge controller. Cutting those posts is probably a good idea. I'm on the 100-year-plan so it takes me awhile to get things done.
 

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Worst case, post's shade should lose 1/2 the power of one panel, so you still get 5/6ths when sun is at an angle. Maybe no need to do anything.

Series string, it could potentially lose 1/2 the array, leaving just 1/2 of production. That's where good MPPT algorithm would make a difference. In parallel, I don't think it would help for yours.
 
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