Hello and a solar controller question

Hedges

I See Electromagnetic Fields!
View attachment 44458
Okay, so here's the PV's. The new 265W panel closest and the 2x 100W panels behind...

A 6-cell panel? that should read about 3 or 4V.

Check voltage of flexible panels. If they haven't failed, probably higher voltage. When disconnected. But if wired in parallel with 6-cell panel, will be pulled down to its voltage.
 

Boatdave

New Member
A 6-cell panel? that should read about 3 or 4V.

Check voltage of flexible panels. If they haven't failed, probably higher voltage. When disconnected. But if wired in parallel with 6-cell panel, will be pulled down to its voltage.
Hi there, thanks for your reply... the voltage of the flexi panels is in a previous photo on this thread - it was 2.2V when the newer 265W single panel was reading around 3.3V at the same time/light of day. The flexi panels are wired into a totally separate controller to the 265W single panel.
Cheers
 

Woody

Solar Addict
You might have a wiring issue.

Let’s start at the panels and confirm voltage. No voltage at panels, then open junction box on panels. Test directly at panel. No voltage, the bad panel. Then trace down the wires and confirm voltage at each junction. No voltage at junction, bad solder/crimp or broken wire. Follow wire down to charge controller. Voltage present? No check wiring. If voltage present, you should be good to go. Oh yeah, do make sure you keep positive and negative wires in their correct connection. You could have them incorrectly connected and negating your power.

Lastly, do make sure your test leads and DVM are good. I have had issues with poor test leads an poor contacts in the DVM so just FYI.
 

Boatdave

New Member
You might have a wiring issue.

Let’s start at the panels and confirm voltage. No voltage at panels, then open junction box on panels. Test directly at panel. No voltage, the bad panel. Then trace down the wires and confirm voltage at each junction. No voltage at junction, bad solder/crimp or broken wire. Follow wire down to charge controller. Voltage present? No check wiring. If voltage present, you should be good to go. Oh yeah, do make sure you keep positive and negative wires in their correct connection. You could have them incorrectly connected and negating your power.

Lastly, do make sure your test leads and DVM are good. I have had issues with poor test leads an poor contacts in the DVM so just FYI.
Thanks for this Woody,
Yep, I get the same voltage (between 3-4V's on midday, English Spring day) at the panel, its connections, and the controller(-s, I've tried a couple) Its just the controller(s) doesn't seem to recognize the panel? Which may well be down to the controller(s) being cheap, not what they claim to be, but dropping £100+ on a decent controller without being sure the panel works as it should is a bit beyond my means presently... hence this questioning/headscratching.
The MM is old and held together by tape, which is admittedly far from ideal, but it seems consistent across its functions thus far (its reads the battery voltage correctly, consistently, etc,) which makes me think it isn't that (yet?!)
Cheers
 

Bud Martin

Photon Sorcerer
Are those panel Voltage readings done with the panel wires still connected to the SCC? If they are still connected to SCC, then what do you get if they are not connected to the SCC?
 

Boatdave

New Member
Are those panel Voltage readings done with the panel wires still connected to the SCC? If they are still connected to SCC, then what do you get if they are not connected to the SCC?
Hi Bud, so far, the same at the panels when disconnected from the SCC as at the SCC when connected. Cheers
 

Bud Martin

Photon Sorcerer
Hi Bud, so far, the same at the panels when disconnected from the SCC as at the SCC when connected. Cheers
"the voltage of the flexi panels is in a previous photo on this thread - it was 2.2V when the newer 265W single panel was reading around 3.3V at the same time/light of day." It just does not make sense to me that two panels have very low Voltage readings, something in common to give bad readings from two panels, the only thing that is common to both is the meter but you said the meter shows the correct batteries Voltage. Try 200V scale or another meter?
 

Boatdave

New Member
C
"the voltage of the flexi panels is in a previous photo on this thread - it was 2.2V when the newer 265W single panel was reading around 3.3V at the same time/light of day." It just does not make sense to me that two panels have very low Voltage readings, something in common to give bad readings from two panels, the only thing that is common to both is the meter but you said the meter shows the correct batteries Voltage. Try 200V scale or another meter?
cheers Bud. Yep, I've had the MM on 20 and 200V setting (both give consistent readings in relation to the settings) I'll try another MM for sure. I know next to nothing about solar panels and am trying to learn some basics, hence these questions... some one previously mentioned that a 6 cell PV (which I'm pretty sure my new 265W panel is, which the cheap controller isn't recognizing despite it having a readable [albeit low?] voltage) should be putting out between 2.5-4 V's, which mine is... does that seem correct to those in the know?
As ever, thanks for your time. Me and my dodgy panels appreciate it (well, I do at least. I have no idea about them?!)
 

Bud Martin

Photon Sorcerer
That 265W LG panel has Voc (Open Voltage, no load) of 38.3V, so the reading should be in 30's Volt range.
 
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Hedges

I See Electromagnetic Fields!


60 cells. 6 x 10 arrangement.

1618087173109.png

In the photo, 6 cells. 2 x 3 arrangement.

I don't see the 60 cell LG panel in the photo.
The 6 cell panel will be about 1/10th the voltage, about 3.8 Voc.

How is this 6-cell panel wired in to your system?
 

Boatdave

New Member
Che

60 cells. 6 x 10 arrangement.

View attachment 44545

In the photo, 6 cells. 2 x 3 arrangement.

I don't see the 60 cell LG panel in the photo.
The 6 cell panel will be about 1/10th the voltage, about 3.8 Voc.

How is this 6-cell panel wired in to your system?
cheers Hedges.
I inherited the panel (albeit new and unused) from a mate and was just going off what it says it is on the rear of the panel. It's not what it says is?
It's wired into a cheap controller labeled "MPPT" (but I think we've established that is fanciful,) the + wire into the + input and the - wire into the - input on the controller, which is then wired into my 3x 12V leisure battery bank, with an inline fuse on the + wire.
Cheers
 

Hedges

I See Electromagnetic Fields!
If the 265W sticker (for a 60 cell panel) was on the back of a 6 cell panel, then it's not what it says.
Hope you didn't pay too much for it :) . If you "inherited" it like got it for free, then no harm.

If the other two flexible panels are connected in parallel with this one, that would explain everything.
But before disconnecting (and possibly putting excessive voltage into PWM SCC), need to review specs of the flexible panels, and test their voltage in isolation, disconnected from SCC.
 

Woody

Solar Addict
Based upon the 2x3 cell panel size it isn’t 300w size but more like 2-4watt. I highlighted your picture to label the panels you noted earlier. Without a close up on the panel to see if those 6 whole cells or 6 big cells sliced and wired together, it’s difficult to tell you what that panel is rated at. Assuming those are 6 whole cell wired in series, then that little solar panel is roughly a 6x0.5v=3v panel that should generate about 1A. So it looks like you have a small 3watt solar panel and your voltage readings are spot on for a 3w 6 cell solar panel. If you‘re try to charge a 12v batter off is tiny panel, you are going to need to boost up the voltage. They do have voltage devices that can boost the voltage (DC to DC Converter also called buck/boost converters) up but the amperage you’ll be feeding into the batteries will be very low in the milliamperes range. You need a bigger solar panel.
 

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Boatdave

New Member
If the 265W sticker (for a 60 cell panel) was on the back of a 6 cell panel, then it's not what it says.
Hope you didn't pay too much for it :) . If you "inherited" it like got it for free, then no harm.

If the other two flexible panels are connected in parallel with this one, that would explain everything.
But before disconnecting (and possibly putting excessive voltage into PWM SCC), need to review specs of the flexible panels, and test their voltage in isolation, disconnected from SCC.
Yep, that sticker is on the little panel (nothing like a curveball straight off the bat to keep the newby on their toes?!) and I inherited it for free, so no harm done there.
It isn't connected to the other flexible panels at all. It has its own, separate, new SCC, which isn't recognising any charge (large, small or otherwise) from the panel, despite it putting out in the region of 3V's on the MM? Which all sounds about right from what I've learnt from the congregation thus far, but which still doesnt answer why the new SCC doesn't recognize the charge from the panel?
 

Boatdave

New Member
Based upon the 2x3 cell panel size it isn’t 300w size but more like 2-4watt. I highlighted your picture to label the panels you noted earlier. Without a close up on the panel to see if those 6 whole cells or 6 big cells sliced and wired together, it’s difficult to tell you what that panel is rated at. Assuming those are 6 whole cell wired in series, then that little solar panel is roughly a 6x0.5v=3v panel that should generate about 1A. So it looks like you have a small 3watt solar panel and your voltage readings are spot on for a 3w 6 cell solar panel. If you‘re try to charge a 12v batter off is tiny panel, you are going to need to boost up the voltage. They do have voltage devices that can boost the voltage (DC to DC Converter also called buck/boost converters) up but the amperage you’ll be feeding into the batteries will be very low in the milliamperes range. You need a bigger solar panel.
Cheers Woody. The 2x 100W flexi panels are hooked up to the battery bank via their own, separate SCC (of which I'm only getting a reading of 2.2V from on the MM. Could they be worn out at that sort of reading? They're old and I've never messed with them, but have wondered about their productivity [without investigating it] before...)
As I say, I inherited the small panel, which is wired into the battery bank via its own, separate SCC (which isn't currently recognizing the panel as working, which was/is my original query)
My thinking was it's a new, free panel, and every little bit of charge to the batteries helps reduced the amount of time I have to run the boats engine to keep the batteries charged... although it isn't working out like that so far?!
Cheers
 

Hedges

I See Electromagnetic Fields!
Assuming those are 6 whole cell wired in series, then that little solar panel is roughly a 6x0.5v=3v panel that should generate about 1A. So it looks like you have a small 3watt solar panel and your voltage readings are spot on for a 3w 6 cell solar panel.

Should be similar current as a large panel with same size cell, maybe 5 to 7 amps. Could be 20W or so. If connected to a boost converter, could be used to keep a 12V battery charged.

BoatDave - you just need some good panels. Don't pay retail. I don't know what deals on used/surplus are in your area, but get 200 to 400W panels for various prices from $0.12 to $0.50 per watt. Panels of around 40 Voc to 60 Voc are typical, and will require an MPPT controller than has input voltage rating higher than that (PV panel voltage increases in freezing weather.) Most MPPT SCC are rated 100, 145, 150, 200, 250, some 600V input. Series connection of multiple panels is often good. Maybe 6 panels, each 40 Voc, wired 3s2p for 120 Voc into a 150V controller.

Or, if your PWM charge controllers are functional, some "12V" panels that are around 21 Voc can be connected in parallel.
 

Boatdave

New Member
All good advice for sure. Thanks.
Before I start spending cash that I haven't really got on new equipment I'd like to learn why the new controller isn't recognizing the new panel's output that I already have here though? So if anyone has any ideas, please fire away...
Cheers, as ever
 
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