Solar panel wire- positive wire hot to touch

[hamrover]

Yes, for a single 200W panel you are more than safe on the 30A fuse.

Also, when carefully configured with multiple 200W panels you will also be safe when operating within the limits of a smaller system like what fits on an RV. Rarely will you reach the peak output of the panels.

That said, there are still wiring choices such as many panels all in parallel which can get you into trouble on the amps. In the pre-charge controller world, letting voltage climb instead of amps is your friend.

There are just too many scenarios to cover them all with blanket statements.

 

[Aussieguy]

Magnificent YUP I know...
Carnac what's that?

 

[miataroadster]

Actually, a few quick amendments - If your charge controller is the GoPower 30 MPPT (I could only find specs for one online) then it looks to be able to accept your setup of 300W x 2 panels (600W) in either config (series or parallel) - so the remaining concern is that right at 30A you are at max capacity for the MC4 connectors, and perhaps slightly beyond. With a 30A inline MC4 fuse, you may occasionally blow the fuse.

Your charge controller will only put out 30A to the batteries ("Rated Current Charge = 30A"), but with 600W on the input side you are right at the capacity of the controller again (and even slightly beyond), so it is likely to see that full 30A much of the time - so best to check those wires for ratings vs the chart above as well. I would expect temps are going to be warm in your current setup, even at the charge controller, and it doesn't leave much headroom for heat dissipation or slight over current conditions. Probably good to make sure those going to the battery are high quality 10AWG or better.

It looks like your charge controller might be leaving a little bit on the table in terms of not being able to pass through your full 600W capacity with that 30A output rating - so if you ever did decide to upgrade it - you would need to re-evaluate the increase in amperage that would result on your wires running to the battery and for sure look at 8 AWG or 6 AWG.

I'm still curious what your split charging looks like - are you using the "dual battery charging" of your solar charge controller to accomplish this?

Before the addition of my 2-200w panels to the original 1-200w panel, I asked GoPower cs if it's okay for me to use same charger. I was told yes.

The setup on the roof is exactly what you have posted. I used Y branch connectors(3 to 1) for each wire polarity going down inside the rv. I also added inline fuses.

Inside the rv, before the GoPower charger, I used one T branch splitter(1 to 2) for each polarity. I installed inline fuse per splitter(overkill?). For easy connect/disconnect I used MC4 connectors.

Looking at the splitter in upright position, one wire from roof going to bottom port of splitter then on top of it are two more ports. One wire goes to the GoPower mppt charger, the other wire goes to the Oupes power station. Same set up for (+) & (-) wires.

I am only utilizing connection of B1 of the GoPower charger for the split.

 

[miataroadster]

then you can put the panels in series to increase the voltage even more
20v x 3 (3 panels in series) = 60v x 10amp = 600w
MORE voltage = less amps for the same total Watts.

Weather permitting, Id experiment on series connection. The only disadvantage is if when I am using the same roof solar array to charge the Oupes powerstation(via splitter) is that panels can only throw max of 10.42 amps. Oh well, at least I don't have to worry about WARM cables.

I was worried about panel shading with series connection. But the GoPower manual says basically, no problem......

Per manual,
"Advanced multi-peak tracking technology. When the solar panel is shadowed or part of the panel fails resulting in multiplepeaks on the I-V curve, the controller is still able to accurately track the maximum power point".

By the way, with my current setup up of parallel connection , some connectors were measured @ 50- 72 deg F. That was from 10am- 4pm sun.

 

[GolfingDave]

Carnac what's that?

Carnac The Magnificent

Apparently you went to sleep before Johnny Carson came on.

 

[hamrover]

Looking at the splitter in upright position, one wire from roof going to bottom port of splitter then on top of it are two more ports. One wire goes to the GoPower mppt charger, the other wire goes to the Oupes power station. Same set up for (+) & (-) wires.

That is pretty cool! I like this idea. I guess both charge controllers are MPPT? It would probably be less than ideal if the Oupes were PWM...

I should have done this with my system. Now you have me thinking about things...

Have you experienced any downsides to this setup?

 

[hamrover]

It looks like your charge controller might be leaving a little bit on the table

One wire goes to the GoPower mppt charger, the other wire goes to the Oupes power station.

Also, in this case I have to retract my earlier statement about "leaving a little bit on the table" - because this setup you have isn't wasting any charge capability despite the 30A charging out limit on your GoPower. What happens is that anything leftover will be available to your other Oupes charge controller. While the real tug-of-war between the two is more complex than that - the fact remains that you have pretty good utilization of whatever your panels are producing.

 

[miataroadster]

Also, in this case I have to retract my earlier statement about "leaving a little bit on the table" - because this setup you have isn't wasting any charge capability despite the 30A charging out limit on your GoPower. What happens is that anything leftover will be available to your other Oupes charge controller. While the real tug-of-war between the two is more complex than that - the fact remains that you have pretty good utilization of whatever your panels are producing.

Using the splitter between the GoPower charger and Oupes power station, no problem. I can see a steady input charge in the power station.

When my coach batteries are charged, I disconnect the line going to Gopower charger. I then connect same line to the Oupes extra Battery. I can see that the input wattage on each Oupes devices is distributed almost equally. However it is not stable- it ramps up and down. That's the down side. The upside is the total input wattage added another 50 watts or so between the two units, and anything over 15 amps is getting distributed to the second unit.

 

[hamrover]

Using the splitter between the GoPower charger and Oupes power station, no problem. I can see a steady input charge in the power station.

When my coach batteries are charged, I disconnect the line going to Gopower charger. I then connect same line to the Oupes extra Battery. I can see that the input wattage on each Oupes devices is distributed almost equally. However it is not stable- it ramps up and down. That's the down side. The upside is the total input wattage added another 50 watts or so between the two units, and anything over 15 amps is getting distributed to the second unit.

Can you just leave them both connected all the time, and let the charge controllers "work it out" ?

 

[miataroadster]

Can you just leave them both connected all the time, and let the charge controllers "work it out" ?

Yes, I can leave the GoPower and Oupes powerstation connected all the time. I don't see a tug-o-war happening. I guess they like each others mppt. I see a constant input charge of high 280 watts.

Now the Oupes powerstation and Oupes battery, their mppts fight one another on who pulls more amps/wattage. Lol. I've ran it for hours like that and I did not see issues or felt(heat). The input charge not constant. Each will jump up and down from 110 to 165 watts. But now I am thinking for only extra 50 watts or so advantage, I think it's just better to just connect the powerstation and battery as one unit. I bought an expandable capacity power station, so basically I can use the supplied cord to daisy chain them. Then charge it that way. I am unsure if there will be bad outcome when 2 mppts are boxing it out for long periods of time.

 

[Aussieguy]

you can always look at a voltage sensing relay that you can set
while the house battery is below 13.6 the relay will stop the power station from charging

then once the house is charged (the more important battery ) the relay allows the power station to be connected to get charged


IF the RV sits for days at a time between trips... you can just let them charge together as is?

 

[hamrover]

So besides my LiFePO4 house batteries, I also rely on a Goal Zero Yeti 1000X power station for auxiliary stuff. I have charged it all different ways: 1)Its own solar panel - which I have to set up outside and run cables, 2)Through a cig-plug from the RV (limited to 5/10A switch - so super slow), 3) The WORST way, by running Inverter, which then has a cable converting back to DC (double whammy facepalm on conversion losses), but it is fast-ish and pushes 120W....

I had also considered a DC to DC charger to pull from house batteries straight into the Goal Zero power station - but off the shelf units are designed around van lifers who have alternators, and the DC-DC chargers wait until they "see" alternator like voltages before they start to send usually....

So, I'm really liking your solution here. Maybe I will get feeling industrious and tear into my solar stuff again next week....

 

[PhilFromMaine]

Typo? Watts?

Question though, wouldn't the Solar Generator limit the amps during charging? OP does not say what unit he has or the current limit it charges at.


Seen that or at least 23 on my Solar Controller and they are flat on the roof, 600 watts.

Thanks for catching that Dave. I meant 600 watts.

(General response to thread)The original post had no mention whether the panels were in series or in parallel. Since things were getting hot, I assumed they were in parallel. Why else would they be hot? Maybe it is just me or the quality of my components, but I have never seen an MC4 fail for some reason.

 

[miataroadster]

you can always look at a voltage sensing relay that you can set
while the house battery is below 13.6 the relay will stop the power station from charging

then once the house is charged (the more important battery ) the relay allows the power station to be connected to get charged


IF the RV sits for days at a time between trips... you can just let them charge together as is?

Interesting. I'll check on that kind of relay.

 

[miataroadster]

So besides my LiFePO4 house batteries, I also rely on a Goal Zero Yeti 1000X power station for auxiliary stuff. I have charged it all different ways: 1)Its own solar panel - which I have to set up outside and run cables, 2)Through a cig-plug from the RV (limited to 5/10A switch - so super slow), 3) The WORST way, by running Inverter, which then has a cable converting back to DC (double whammy facepalm on conversion losses), but it is fast-ish and pushes 120W....

I had also considered a DC to DC charger to pull from house batteries straight into the Goal Zero power station - but off the shelf units are designed around van lifers who have alternators, and the DC-DC chargers wait until they "see" alternator like voltages before they start to send usually....

So, I'm really liking your solution here. Maybe I will get feeling industrious and tear into my solar stuff again next week....

Hahaha. I have nothing else to do this week that's why I'm tinkering with this. Tomorrow maybe I'll go with series connection with my panels.

Here's one that you can use and can give you up to 300w. They also have another model good for 400w. Both pure sine wave output. Will be good while driving. YT Hobo guy recommends the first one. Charge the battery with this. Then charge the powerstation with your rv roof solar array.

Amazon.com

a.co

 

[miataroadster]

Thanks for catching that Dave. I meant 600 watts.

(General response to thread)The original post had no mention whether the panels were in series or in parallel. Since things were getting hot, I assumed they were in parallel. Why else would they be hot? Maybe it is just me or the quality of my components, but I have never seen an MC4 fail for some reason.

Yes, parallel connection.
I concluded the MC4 was inferior quality. After the new replacement, as of this afternoon, warmest MC4 inline fuse surface temp is up to 93F for a second, then lowers to 60s - 80s. Must be hotter when more amps going thru wire (better panel sun exposure). Wires located in close space. I have been running it from 9am til now, 3pm. Coach and powerstation being charged using the splitter system.

So tomorrow I'll do a panel series connection and retest everything and compare results.

 

[TexasJackKin]

This is all very interesting, just tagging so I'll be notified when there are new posts...

 

[hamrover]

Hahaha. I have nothing else to do this week that's why I'm tinkering with this. Tomorrow maybe I'll go with series connection with my panels.

Here's one that you can use and can give you up to 300w. They also have another model good for 400w. Both pure sine wave output. Will be good while driving. YT Hobo guy recommends the first one. Charge the battery with this. Then charge the powerstation with your rv roof solar array.

Amazon.com

a.co

Well shoot. I'm back to square one.

Since I so wisely wired all my panels in 3s x 2p to keep volts high and amps down - it turns out my incoming volts to my existing MPPT controller are in the 60V range - and my Goal Zero caps out at 50V on the input side - so I cannot directly share my array as is the way that you have done.

I don't move around a lot since I'm in my RV living full time. I also 100% boondock - so no hookups - no shore power - and no car charging.

Back to the "dual charginig" output idea from one single solar array... I don't want to alter my existing panel wiring as the layout was very specifically laid out to favor my 3s x 2p...

Maybe the answer is to just squeeze in one more small dedicated panel for the Goal Zero power station - which means new roof holes.

 

[Aussieguy]

if you not moving a lot make up a ground panel or 2

2 x 400w would be a good addition.
2x4 frame is easy to assemble and take apart to move if ever needed..

go big or go home
you can probably get the bigger 400w for same price as smaller niche 200w

storage while moving... add a couple brackets on the back wall... like they do for the sewer totes
-------------------------------------------------------------------------------------
Alternative idea... use your rail mount on the roof to add a couple of panels over the top of the slide
may take 30 minutes and a ladder to install each time you infrequently move

but gives you a high tech... slide topper and shade /protection for the slide roof

 

[miataroadster]

I agree with Aussieguy on the ground panel/s.
But if you are worried about them walking away, you could use

Corner Bracket Solar Panel Roof Drill-Free Mount.​

You can just glue those brackets on the roof and slip the panel down to it. Windproof. Then remove the panel before moving to another location.

OR
Check on dc to dc step-down converter to still be able to use your roof soalr arrays?