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Ian Holl
07-13-2012, 08:32 AM
Hi,


I bought a 120 Watt Mono Crystalline PV Solar Panel off Ebay from a reputable seller a couple of years ago for camping although I'm yet to get it working properly. I also bought a PWM 10 amp charge controller although as soon as I plugged the solar panel in it burnt the controller out. Believing the controller to be faulty I bought another off Ebay as they're only 13. Again it blew the controller. Although when I took the controller apart to check the damage I notice this time the controller had a fuse so rather than burn the controller out it blew the fuse. The fuse is not replaceable as it's soldered to the PCB board.

My setup is simple. I've connected the controller to my car battery that's still connected to my car and the the solar panel is connected to the charge controller and obviously the supply outlet is connected to provide pover to my appliances, i.e laptop, phone chargers, light chargers.

I bought the panel soley for camping so I could feed from the car battery and keep it topped up with the solar panel. When I've checked the output of the solar panel with a multimeter it's outputting 21/22 volts. Give the charge controller says it 12/24 volt I wouldn't have thought it would have caused the blowing of the charge controller.


Any suggestions please as I'm off camping again next week and I'd ideally like to get this solar panel working



Cheers Ian

epsgunner
07-13-2012, 09:37 AM
Have you checked the voltage coming from the MC4 leads.. using a multi-meter set at higher than 20 volts DC.. you should be at about 19 volts or so form the short leads.. (should be near the VOC numbers in good sun)..

This will also confirm the HOT/COLD leads for you.. some overseas mfg's have in the past had wires mislabled..

The panel specs should be on the back on a sticker.. the amps should be there also.. like 5-6 VMP.. and a higher number for ISC..

A $26 charge controller does not sound good to me.. I wouldn't go less than $50 for one..(about 26 of L)

Maybe a Morningstar SunSaver 10 would work for you.. they make a 12v model.. its like $48 US..

Sunking
07-13-2012, 10:31 AM
Ian my educated guess is you connected the either the battery or the panel reverse polarity. I assume you connected the battery before the panel right? When you connect the battery you should see the controller come to life.

Ian Holl
07-13-2012, 06:33 PM
Thank you for your replies guys, and here's the following labelled spec of the solar panel itself.



Model:
SV120-24-M

Maximum system voltage 1000V
Maximum power intensity (Imp) 4.84A
Short circuit current (Isc) 5.26A
Maximum power point (Vmp) 25-20V
Open circuit voltage (Voc) 30.73V
Maximum power (Pmax) 120W


I've taken on board what's been said, and yes it's possible that I may have reversed polarity the connection.

Checking the polarity of the solar panel itself, with the multimeter's red probe connected to the solar panel's negative and the multimeter's black probe connected to the solar panels positive I get negative polarity. In short red on red and black on black results in positive polarity. But black on red and red on black results in negative polarity.

Hope this helps.


Cheers ian

Ian Holl
07-15-2012, 01:55 AM
Update: I checked the car battery terminals with a friend yesterday as I'm colourblind and I definitely did not reverse polarity the controller with the batery, I'm questioning the quality of the controller as I can't remember it coming to life when I wire it to the battery and I noticed that even though it was a 10 amp controller it had a 30 amp internal fuse.

I wondering if I just so happen to have bought 2 dodgy controllers as I agree that 12 is a bit cheap. I did wire the battery first as it states to wire the battery before the panel.

I'm now contemplating buy a more expensive 30 amp controller although I seriously don't want to bugger that one. My questions are how do I find what wire is hot ( live) with a multimeter and would running an inline 10 amp fuse betweeen the solar panel and controller protect the controlle from reverse polarity?



Help much appreciated

Cheers

inetdog
07-15-2012, 03:12 PM
... would running an inline 10 amp fuse betweeen the solar panel and controller protect the controlle from reverse polarity?

Help much appreciated

Cheers

As a general rule, fuses will protect semiconductor electronics (almost everything these days) from catching fire and burning your house down, but are far too slow acting to be of any help at all in protecting the electronics themselves from meltdown. Anything which really protects the electronic components will be in the form of self-protection designed in at the start (and costing more than 12) or a crowbar circuit that sacrifices itself to cause the fuse to blow (also usually costing more than 12). Fuses are at their best in protecting wires.

PNjunction
07-15-2012, 04:36 PM
... I've taken on board what's been said, and yes it's possible that I may have reversed polarity the connection. ..

I've encountered cheap controllers that were actually wired internally with the wrong polarity to begin with, or the quick-connect adapters had reversed polarity too. So you may be doing everything right, but the quality control of the cheap end makes you trace every polarity up to and including the internal wiring yourself.

Ian Holl
07-16-2012, 09:24 AM
I've encountered cheap controllers that were actually wired internally with the wrong polarity to begin with, or the quick-connect adapters had reversed polarity too. So you may be doing everything right, but the quality control of the cheap end makes you trace every polarity up to and including the internal wiring yourself.

Agreed, I've noticed the charge controller that I bought 2 of and had both fail are now on Ebay for 10 with free delivery from China :eek: For that price they can only be junk. I did a little digging around and although a Chinese Steca 'rip off', the Pangfusun 30 amp PR3030 seems to be a good buy, so I bought one from a reputable seller for 65.

I would have bought a Steca, but for almost twice the price I couldn't warrant it. The Pangfusun's specification states that it has reverse polarity protection and an electronic fuse so time will tell.

Both the battery's polarity and my solar panel's polarity have both cheeked out to be correct, and given that I triple checked the connections before conecting up the controller, (battery 1st), I can only assume that the controllers were indeed reverse polarity wired.

Now I'm learning abit about solar panels I see the 120 panel I bought 2 years ago has a poor amp output that's not that much better than a 80 watt :( I think I will have to see for myself what it outputs when I get it wired.

Hopefully the new 30 amp controller I ordered will do the job. I know it's overkill although I wanted to futureproof the controller in case I later decide to add more panels.



Cheers Ian

Wy_White_Wolf
07-16-2012, 02:17 PM
Thank you for your replies guys, and here's the following labelled spec of the solar panel itself.



Model:
SV120-24-M

Maximum system voltage 1000V
Maximum power intensity (Imp) 4.84A
Short circuit current (Isc) 5.26A
Maximum power point (Vmp) 25-20V
Open circuit voltage (Voc) 30.73V
Maximum power (Pmax) 120W


I've taken on board what's been said, and yes it's possible that I may have reversed polarity the connection.

Checking the polarity of the solar panel itself, with the multimeter's red probe connected to the solar panel's negative and the multimeter's black probe connected to the solar panels positive I get negative polarity. In short red on red and black on black results in positive polarity. But black on red and red on black results in negative polarity.

Hope this helps.


Cheers ian

Panel voltage is to high for the 12v controller. This panel is designed for grid tied systems. If you want to us this panel on a 12v system you will most likely need to find a MPPT controller.

WWW

billvon
07-16-2012, 03:57 PM
Maximum system voltage 1000V
Maximum power intensity (Imp) 4.84A
Short circuit current (Isc) 5.26A
Maximum power point (Vmp) 25-20V
Open circuit voltage (Voc) 30.73V
Maximum power (Pmax) 120W

For your purposes you want a panel with an Vmp of 18 volts or so. Cheap controllers may not be able to handle the higher voltage.

inetdog
07-16-2012, 05:01 PM
For your purposes you want a panel with an Vmp of 18 volts or so. Cheap controllers may not be able to handle the higher voltage.

And since the charge controller may at some point be delivering very little current to the battery, Voc is the critical thing to look at, especially when the panels are cold. Bill is telling you that with a Vmp of 18, the Voc will probably be OK too, but it does not hurt to look at the detailed specs to confirm.

Ian Holl
07-17-2012, 06:26 AM
And since the charge controller may at some point be delivering very little current to the battery, Voc is the critical thing to look at, especially when the panels are cold. Bill is telling you that with a Vmp of 18, the Voc will probably be OK too, but it does not hurt to look at the detailed specs to confirm.

So does this mean the Fangpusun PR3030 isn't any good either? So what you're saying it's the VMP that's been burning out the cheap charge controllers and not negative polarity.

I'm stumped because I've bought the above charge controller although that too may be no good :(


The spec of the Fangpusun PR3030:

http://www.pvsolarchina.com/fangpusun-pr-1010-pr-1515-pr-2020-pr-3030-solar-charge-controller.html


Cheers Ian

inetdog
07-17-2012, 06:56 PM
So does this mean the Fangpusun PR3030 isn't any good either? So what you're saying it's the VMP that's been burning out the cheap charge controllers and not negative polarity.

I'm stumped because I've bought the above charge controller although that too may be no good :(


The spec of the Fangpusun PR3030:

http://www.pvsolarchina.com/fangpusun-pr-1010-pr-1515-pr-2020-pr-3030-solar-charge-controller.html


Cheers Ian

The Fangpusun PR3030 is probably covered by this limit, although the table is a little strange. My assumption is that it applies to all models:

"Open circuit Voltage solar panel <47V"
Note that it refers specifically to Voc, not Vmp.

Since 30.8 is below 47 and since even at cold temperatures the output of the panel you have will probably not go above 47, you *should* be OK.

Ian Holl
07-18-2012, 05:00 AM
The Fangpusun PR3030 is probably covered by this limit, although the table is a little strange. My assumption is that it applies to all models:

"Open circuit Voltage solar panel <47V"
Note that it refers specifically to Voc, not Vmp.

Since 30.8 is below 47 and since even at cold temperatures the output of the panel you have will probably not go above 47, you *should* be OK.




Thank you for the reply. Hopefully the controller will handle it. But looking at the specification of the panel I've currently got and its size I might in the long run sell it and change it for an 80 watt folding type as its for camping, and if the wattage and size of my current solar panel isn't going to give me a significant advantage over the smaller more efficient 80 watt type it's time to sell the 120 watt panel.

Ian Holl
07-18-2012, 06:52 PM
Tonight I wired up my new Fangpusun 30A controller by the book, ensuring I wired the battery, solar panel and then the load. However, the controller showed an error code of reverse polarity :Cry: Suddenly the penny dropped! I dug out my 'probe and tone' and tested the continuity of the negative and positive of the so called 'idiot proof' connections of a solar panel cable kit which I purchased from Maplins and it turns out that part of the connecting extension cable has been manufactured reverse polarity by mistake Argghhhh!!!!!


Problem solved!



Thanks to all who have helped with this thread.

Sunking
07-18-2012, 07:00 PM
Post #3

Ian my educated guess is you connected the either the battery or the panel reverse polarity.


I dug out my 'probe and tone' and tested the continuity of the negative and positive of the so called 'idiot proof' connections of a solar panel cable kit which I purchased from Maplins and it turns out that part of the connecting extension cable has been manufactured reverse polarity by mistake Argghhhh!!!!!

Thanks to all who have helped with this thread.

You are welcome.

inetdog
07-18-2012, 07:30 PM
I dug out my 'probe and tone' and tested the continuity of the negative and positive of the so called 'idiot proof' connections of a solar panel cable kit which I purchased from Maplins and it turns out that part of the connecting extension cable has been manufactured reverse polarity by mistake

IMHO from personal experience, you can make things idiot-proof, and sometimes you can even make them engineer-proof, but you can never make them physicist-proof.

PNjunction
07-19-2012, 04:20 PM
.. I dug out my 'probe and tone' and tested the continuity of the negative and positive of the so called 'idiot proof' connections of a solar panel cable kit which I purchased from Maplins and it turns out that part of the connecting extension cable has been manufactured reverse polarity by mistake Argghhhh!!!!!..

Yes! Glad you found it. I went through the same thing a few years ago with a Sunforce / Harbor Freight single-panel kit. Sure, when used on it's own, the quick-disconnects were in the proper polarity. Later, I lost the jumper clips, and replaced them with one from a charger that had the same quick-disconnect design. POOF!

Turns out the charger jumper had the more universally accepted polarity wiring. Lesson for me: when going cheap, especially when mixing different vendor's wiring, doublecheck the real polarity first.

Ian Holl
07-20-2012, 07:39 AM
Yes! Glad you found it. I went through the same thing a few years ago with a Sunforce / Harbor Freight single-panel kit. Sure, when used on it's own, the quick-disconnects were in the proper polarity. Later, I lost the jumper clips, and replaced them with one from a charger that had the same quick-disconnect design. POOF!

Turns out the charger jumper had the more universally accepted polarity wiring. Lesson for me: when going cheap, especially when mixing different vendor's wiring, doublecheck the real polarity first.


All of my quick connections were bought as one kit. However, last night I connected the kit's 5 meter extension cable and that too checked out to be reverse polarity :mad: The whole kit is flawed because the manufacturer's clips puts a positive to a negative and a negative to a positive. The only way this will work is if the kit's extension cable is connected up with 3 parts as that way it will right itself. Although it's designed to only by connected twice as the extention only has one quick connection end. The other end are bare wires. In order to get the kit's crocodile clips in the right polarity is to cut off the quick connections because as soon as you connect the quick connect it reverses the polarity, as does the kit's male and female cigarette sockets.

As no part of the kit has a cable with 2 quick connects on each end I cannot correct the polarity, so I'll just have to relabel the the positives and negatives to opposite unless I go out and buy an extension with 2 quick connect ends. I'm off to Maplins now to complain to to see if they'll cough up an extension as their dodgy kit's cost me money and time :@


Cheers Ian

Ian Holl
07-20-2012, 11:22 AM
Well, I went to Maplins today and complained about their Solar Kit being flawed with the reverse polarity. The shop assistant and I tried a double ended extension lead to see if it corrected the polarity, although it never. After a bit of head scratching another shop assistant claimed the Solar Kit was for one of their solar panels. I argued that the quick connection doesn't plug into a charge controller. I refered to the Maplin's catalogue and found the Solar Kit and pointed out that there's no mention of it being for a specific panel.

Off the assistant went and fetched a trickle charge solar panel from the shelve and pointed out the identical connection. Apparently even though there's absolutely no mention of it whatsoever the Solar Kit is only for that solar panel as the connections on the panel itself are compatible, (reversed), to right the polarity.

The shop assistant was very apologetic and said he was contacting the manufacturer and head office about the description of the kit as it should have stated that the kit was for use for a "specific solar panel only". I shall continue to use the kit, albeit wire it reversed.

PNjunction
07-24-2012, 08:22 AM
I went to the Maplins site, and on this side of the pond, the panels are the same Sunforce panels, sold typically in the Harbor-Freight stores. They also used to be seen at Camping World. One of the accessories for the Sunforce panels seen on the Maplins site is the quick-disconnect that caused me the same wrong-polarity grief when used with anything but the original panel wiring.

I guess don't blame Maplins, but Sunforce for being non-standard.