Foldout Solar panels wiring questions ...

[Hodge]

So, I'm going to utilize the solar function of my Redarc BCDC1225...
BCDC is wired as a normal dual battery system now, only fed off the alternator ...

The end result will be this setup. With an anderson plug at the front of the car. Together with the switch over relay which arrived today.


http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64452&stc=1
http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64453&stc=1

My question is in regards to the solar panel.... Mine arrives wednesday, but they have the similar setup to the photo below...
Now do I by-pass those control boxes all together on the panels, since the BCDC will be doing the "control" work, or do I leave it as is, and plug the panels in as they are ??

So on the photo you can see a cable going from right panel into a "junction box?" on the left and then into the control box... Is that
a series wiring, or are the panels paralleled at the black box on the left?
As above I dont have my panels yet so don't know the exact setup. Trying to set it all up before weekend as I am going away now and weather will be solar-perfect ...


http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64454&stc=1

[megatexture]

Depends on the quality of the wires supplied if they are rubbish Just remove the covers on the back of the panel and solder new wires on the same way they have it but of a better gauge.
No need to include the reg on the panel as the redarc will do it all but personally I'd not remove it just put a quick release plug on it between reg and panel as it may come in handy one day to use without the redarc.

My guess would be they are 2x60w panel in parallel

[the evil twin]

No need to change the panel interconnects (black box to black box) and assuming you want to use Andersons...

For dedicated BCDC use...
1 Remove the two wires that go to the Reg Input from the Solar Panel 'Black box' and fit an Anderson plug tp them (lets call this the Solar Panel Output).
2 Remove the two wires currently connected to the Battery terminals of the Reg and fit an Anderson plug (lets call that the Supply lead)
3 Remove the Battery Clamp fly lead from the supply lead and store for later
4 All you now need to do is connect the Anderson on the supply lead to the Solar panel Output and the other end to the Anderson on the Car that goes to the BCDC

Now... if you ever want to use the Panels as stand alone then as well as above;
Make up two short flyleads of 12 inches or so with an Anderson Plug each and attach them to the Solar Reg panel and battery terminals
To use the Solar panels as stand alone plug the Solar panel Output Anderson into the Reg Solar Anderson and your Supply lead into the 'battery' Anderson of the Reg and the Battery Fly lead into the other end of the Supply Cable

[mudski]

I don't have a relay wired in to the 1225 on my camper. And i can have solar or car charging...The way Eric wants it may need the relay though...

Sent from my SM-P600 using Tapatalk

[Hodge]

Ok thanks a lot for the replies !! Clears up exactly what I was asking...




My guess would be they are 2x60w panel in parallel

Yeah it is a 120W array setup. This very model from this very shop.

http://www.lowenergydevelopments.com.au/Folding-Solar-Panel-120W

Thanks ET !! Described it perfectly ... I've conjured up this quick drawing in paint... So in a nutshell I bypass reg panel (blue filled box) altogether for in-car bcdc setup....
In the diagram below the point where I have anderson plug will be at the bullbar somewhere for easy plug 'n play action.


http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64460&stc=1

[Hodge]

I don't have a relay wired in to the 1225 on my camper. And i can have solar or car charging...The way Eric wants it may need the relay though...

Sent from my SM-P600 using Tapatalk

Yeah mate exactly and which is why I got that redarc switching relay for purpose designed for this scenario. Well, I could have got any ordinary relay but this already had wires pre-crimped and lugged ready to go with everything needed.

[Cuppa]

Looks like you have it sussed. This is the setup for auto switching between solar/alternator. Works well. Turn on ignition & alternator charges the battery. Turn off ignition & it defaults to solar when panels are permanently mounted or portables are connected via the anderson plug. I have the same setup with roof mounted panels.

Check out this link http://hobohome.com/news/?p=581 to determine what size cable to use between panels & the BCDC. The supplied cables will not be heavy enough & voltage drop will have a significant effect on charging efficiency. If you think that you may add further panels in the future, base your cable size on that, having it heavier than required at the moment will do no harm. I have found that it is worth using a 10 metre cable for portables as it often allows for vehicle to be parked in the shade but still have the panels out in the sun.

[threedogs]

Looks like you have it sussed. This is the setup for auto switching between solar/alternator. Works well. Turn on ignition & alternator charges the battery. Turn off ignition & it defaults to solar when panels are permanently mounted or portables are connected via the anderson plug. I have the same setup with roof mounted panels.

Check out this link http://hobohome.com/news/?p=581 to determine what size cable to use between panels & the BCDC. The supplied cables will not be heavy enough & voltage drop will have a significant effect on charging efficiency. If you think that you may add further panels in the future, base your cable size on that, having it heavier than required at the moment will do no harm. I have found that it is worth using a 10 metre cable for portables as it often allows for vehicle to be parked in the shade but still have the panels out in the sun.

Your panels are mounted permanently on the roof arent they??

[the evil twin]

Your panels are mounted permanently on the roof arent they??

Permanently? ... mmmmm... that probably depends what suburb he parks his car in.

[Cuppa]

Permanently? ... mmmmm... that probably depends what suburb he parks his car in.

Any scumbag wanting to relieve me of my panels would need to be fairly committed & come equipped with the right tools, a ladder, a means to carry them away & spend an hour or two to remove them. It’d probably be easier to just steal the car & there is a big selection of less identifiable vehicles out there to choose from. (Touching wood).

[threedogs]

Any scumbag wanting to relieve me of my panels would need to be fairly committed & come equipped with the right tools, a ladder, a means to carry them away & spend an hour or two to remove them. It’d probably be easier to just steal the car & there is a big selection of less identifiable vehicles out there to choose from. (Touching wood).

Just saying its defeating the purpose isnt it having to park your Patrol
out in the sun everything will be working harder to remain cool.
Sorry but I just dont see the point of mounting them permanently, one you
cant chase the sun well you can but you need to start your Patrol to move them.
But its your set up and if its works for you so be it, lol

[mudski]

Just saying its defeating the purpose isnt it having to park your Patrol
out in the sun everything will be working harder to remain cool.
Sorry but I just dont see the point of mounting them permanently, one you
cant chase the sun well you can but you need to start your Patrol to move them.
But its your set up and if its works for you so be it, lol
I have a 100w perma mount panel on my rack and its plenty. You dont need to chase the sun at all.
It would take a couple of days of no no sun and no engine running to flatten the battery.
How many times would anyone be in a situation like that?
I was skeptical first by perma mounting but now i think its great.
Even today. I was at BA's place. It was raining and my panel was still charging at 13.2v.
Since mounting the panel i have noticed the battery voltage sits at around 12.9v where it used to sit at 12.7v or lower.

Sent from my GT-N7105T using Tapatalk

[Cuppa]

Just saying its defeating the purpose isnt it having to park your Patrol
out in the sun everything will be working harder to remain cool.
Sorry but I just dont see the point of mounting them permanently, one you
cant chase the sun well you can but you need to start your Patrol to move them.
But its your set up and if its works for you so be it, lol

Mate, depends partly on how many panels you have, & what the usage pattern is. Having to constantly move portables around throughout the day becomes a chore, particularly so once you have more than a couple, far easier to have enough extra capacity to not need to bother doing that & I sure don’t miss the unpacking, setting up, packing away part of the routine. What’s ok for an occasional weekend quickly becomes a pain when needing to do it every morning & evening for weeks & months at a time I can assure you. I think you often forget that aspect.

As for parking the Patrol in the sun - no biggie, I can put the Patrol in the sun & have the Tvan nearby in a shadier spot. It’s a non issue. Was also never a problem when we had the bus, Heat reflective paint, roof insulation + the panels creating a ’tropical roof’ , plus a awning & sunblock curtains & good internal airflow made for a comfy home on the road without needing to chase shade.

Added bonus is that the panels are a lot more secure & less likely to have someone walk off with them than portables.

[Hodge]

Well my panels arrived today and I wired up everything on the BCDC receiving end including the switch over relay. Just gotta cut the cables behind the panels, crimp in some plugs and then wait to test it all out .....

http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64568&stc=1http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64569&stc=1

[megatexture]

I floss with wire like that, I'd be upgrading the lot but that's just me.

[the evil twin]

Any scumbag wanting to relieve me of my panels would need to be fairly committed & come equipped with the right tools, a ladder, a means to carry them away & spend an hour or two to remove them. It’d probably be easier to just steal the car & there is a big selection of less identifiable vehicles out there to choose from. (Touching wood).

Dare ya to come over here and park it at Perth Airport...

[Cuppa]

I floss with wire like that, I'd be upgrading the lot but that's just me.


:) Nice image.

The wire between the two junction boxes will be ok, but definitely go heavier on the cable between panels & BCDC. What gauge cable do you have with the anderson plugs fitted?

[Hodge]

:) Nice image.

The wire between the two junction boxes will be ok, but definitely go heavier on the cable between panels & BCDC. What gauge cable do you have with the anderson plugs fitted?

The whole lot from the BCDC , through the relay all the way to the solar panels is 8AWG (8.36mm2) hydraulic-crimped.
The cables from panel to panel, and the cables they included were all 4mm2.

[Hodge]

All wired up ready for the sun.
Excuse the following solar amateur question...
Is it normal for a solar regulator/charger not to charge below 17V or so under no load? Or is it mainly the bcdc chargers that do that ? Or maybe even only redarc?
It's 20% sunny now and I'm getting 15-16V at the connectors.... And the redarc isn't kicking in, so I dug this table up and it sort of made sense then.

Not the table below... Under no load, shuts off below 17.2V. This is my Redarc BCDC1240 unit rules. Am I understanding this right?
I assumed even at 15-16V the unit may keep "float" charging the battery....




http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=64602&stc=1

[Nightjar]

Not too savvy on electrics.
Question: Does the ignition need to be left "on" for the panels to charge in the above set up?
If so, why not just use the panels + solar controller and connect directly to battery via a Anderson plug?

[Hodge]

Still sort of cloudy-ish, but the volts out of panels are now 19-21V, and the Redarc is now happily keeping the whole thing "floating". So far it works... Going to be very sunny next 3-4 days when I'm going away so, it'll be great having that keeping the charge up while car is sitting there.





Not too savvy on electrics.
Question: Does the ignition need to be left "on" for the panels to charge in the above set up?

No. Which is the whole purpose of the switchover relay coupled with the redarc bcdc. If ignition is on, and car is running and the primary battery / alternator volts are above 13 or something, the unit is charging from that...
If ignition is off, the relay switches over to solar input and charges from there if the panels are plugged in and the voltage conditions are right. It is a set and forget system ... Especially for people with permanent mounted panels, like on the roof or something.




If so, why not just use the panels + solar controller and connect directly to battery via a Anderson plug?

[the evil twin]

All wired up ready for the sun.
Excuse the following solar amateur question...
Is it normal for a solar regulator/charger not to charge below 17V or so under no load? Or is it mainly the bcdc chargers that do that ? Or maybe even only redarc?
It's 20% sunny now and I'm getting 15-16V at the connectors.... And the redarc isn't kicking in, so I dug this table up and it sort of made sense then.

Not the table below... Under no load, shuts off below 17.2V. This is my Redarc BCDC1240 unit rules. Am I understanding this right?
I assumed even at 15-16V the unit may keep "float" charging the battery....



Hiya Cobber,

For most MPPT Regs, yes that is normal becauuse if the O.C. voltage is below 17.5 then it isn't seeing the Sun

To get the system to 'initially' turn on it needs to see 17.5 Volts but may take up to a minute and a half to do so.
If there is no load and the Panel voltage drops below 17.2 the Reg turns off until it sees 17.5 volts again
If there is a load being drawn (IE something is connected and not just an Anderson swing in the breeze) the Reg will ignore the 17.2 Volt threshold and drag as much as it can from the Panels unless the voltage drops to 8 Volts (IE the sun goes away)

Hope that helps

[Hodge]

Thanks ET ! That is exactly what's been happening, I've been monitoring it and playing with different scenarios and all those rules check out.

It's funny the "raw" open circuit volts of the Panels sometime shoot above 20V ! It's sitting on just below 20 as I type this as it's in full sunshine.

[the evil twin]

Thanks ET ! That is exactly what's been happening, I've been monitoring it and playing with different scenarios and all those rules check out.

It's funny the "raw" open circuit volts of the Panels sometime shoot above 20V ! It's sitting on just below 20 as I type this as it's in full sunshine.

Yep, that 20 to 21 Volts is normal... you should have a sticker on teh Panel that has "VOC" or "Open Cct Voltage" or somesuch and then a voltage value.

The 17.5 Volts (give or take) that the Reg is looking for is the peak of the Power Curve knee.
IE that is where the panels produce the most useable power IF you have a true MPPT reg.

While we are chatting, you will also have a "Short Circuit Current" rating with an Amps value.
To test a Panel, with nothing connected and preferably at the terminals on the back of the panel in full sun and at 90 degrees plane
Check the VOC value and note the actual versus stated.
Check the Short Circuit Current (make sure you select the correct current range then just short it straight acrosss the Meter)
Work out the difference in percentage and that is how much the Panel has deteriorated
EG say the VOC was 18 and the sticker was 20 then 18 is 90% of 20 or if the Current was 3.6 amps instead of 4.0 Amps then same thing.

Depending on quality... Panels will deteriorate approx 1 to 2 % per year as normal.
Better than that, good for you, worse than that, bummer dude...