After picking up the motorhome from storage yesterday we noted that the batteries were not up to their usual standard of charge,(12.4v leisure and 11.5 van) and that the solar panel regulator, an Alden SPS110, had an led light showing "down 20%", which I understand means charging. However, on looking at the Sunware Fox LCD Display it was showing 00.0 amps.
This was confusing considering it was a very bright, hot, blue sky day with plenty of sunshine. So, the 85w solar panel should have been charging quite a respectable current.
On getting home I got the multimeter out and have the following readings which don't make sense:-
Whilst the solar panel was connected to the regulator and the regulator connected to the EBL99 (the load and batteries), I found 12.9 V from the solar panel connector at the regulator and 12.7V from the regulator to the EBL, and these appears sensible to me. Being very careful and with the Silver screen across the solar panel to kill any current, I then disconnected the solar panel. On removing the Silver screen I noted 19.7-20.4V as a raw solar panel voltage. This again looked OK.
I then reconnected the solar panel back to the regulator but this time included the multimeter connected in series through the 10A point on the multimeter. The reading was 0.00 amps???? I removed the multimeter and this time connected it in series from the regulator to the EBL. The reading was 0.01 amps.???
So I think I have confirmed that the solar panel is not charging therefore the question is why?? The regulator appears to be controlling the voltages normally but no current is being seen. Is this likely to be the regulator or the panel thats faulty? Please don't say the 85w panel.
I have checked the panel on the roof and there is no damage and no cracks. All appears normal and the panel is clean. It's mounting bracket is silkaflexed to the roof, so although I can see the wire going into the junction box under the panel, I can't get at it. However, the cable from the panel appears undamaged. This system was working normally when the van went into open air storage 5 weeks ago.
Disconnect the panel and short circuit the panel with the 10A range of your multimeter you will then get the Isc reading for the panel and you can compare that with a typical spec for a 85 W panel which will be around 5A in full sun.
I suspect the regulator
______________________________________________________________ Regards Frank - - Denn wir haben nichts in die Welt gebracht; darum offenbar ist, wir werden auch nichts hinausbringen.
RIP Peter and Fiona Our thoughts are with you Chris and Graham. Fighting with Mavis and Ray
Plusnet, Safari 5, G5 PowerPC iMac running OSX 10.5.8, Salisbury UK : Get behind early - it gives you more time to catch up.
I did not know one could just short the panel across the multimeter to read current flow, with no load. I suppose then that the multimeter provides the load.
So I have just disconnected the panel again from the regulator. It read 20.5V in bright sunlight but was reading 00.0amps on the 10A scale. I switched the cables down to the lower reading connection on the multimeter(max 0.2A) and found it reading 0.85 while set to 20m in the amp range. I'm assuming this means 20milliamps and therefore the panel is producing 0.8 milliamps, i.e. 0.008amps.
Oh bugg**. I suppose this means the solar panel has given up the ghost for some unknown reason.
Right now we know that the short circuit current is approx zero.
Is it possible to get to the junction box?
This has all the symptoms of a high resistance contact. Your DMM has such a high impedance on its volt ranges that it will effectively ignore a high resistance when measuring open circuit voltages. Its very low impedance on the Amp ranges ensures that if there is a high resistance in the circuit that it measures then all the voltage will be dropped across that high resistance an no or very little current will flow. Your battery is also a low impedance.
So you may be lucky and find that it is a high resistance contact in the junction box or a high resistance blocking diode but unfortunately it can easily be a dry joint within the panel or a cracked piece of silicon.
______________________________________________________________ Regards Frank - - Denn wir haben nichts in die Welt gebracht; darum offenbar ist, wir werden auch nichts hinausbringen.
RIP Peter and Fiona Our thoughts are with you Chris and Graham. Fighting with Mavis and Ray
Plusnet, Safari 5, G5 PowerPC iMac running OSX 10.5.8, Salisbury UK : Get behind early - it gives you more time to catch up.
Shorting the solal panel with an ammeter is the easiest & quickest way of checking the panel is producing "power"
If you've determined that the short circuit current is effectively zero then as Frank says you'll have to have a look inside the junction box on the rear of the panel. It's a bit of a mystery as the voltages you're seeing sound the same as I recorded from my panels.
Good luck in your quest. Let us know what you find.
Sorry for my late reply but have just got back from the New Forest and a red hot south coast beach, so have been without internet.
I will follow your advice and try and get to the black junction box on the underside of the panel. Unfortunately, as the solar panel is fixed to the roof on its Alden supports with sikaflex, I cannot get at it, as the gap around the edge is too small. I will try again tomorrow, but I think I will have to find a way to break the sikaflex bond and remove the panel.
Interestingly, whilst away I spoke to Eddie from Vanbitz and he suggested checking the connections within the junction box as apparently they can easily become loose if not fitted correctly. His point was that a poor connection would breakdown upon any reasonable draw, but still show a good voltage when not under load.
Thanks again and I will let you know how my investigation goes.
In my perhaps over technical way that is what I was saying and its why without a bit of extra thought voltage on its own can be such a poor diagnostic tool.
As to Sikaflex how many different Sikaflexes are there? I would start with a bit of white spirit having tested it on a hidden piece of your van first. That and a razor sharp knife.
______________________________________________________________ Regards Frank - - Denn wir haben nichts in die Welt gebracht; darum offenbar ist, wir werden auch nichts hinausbringen.
RIP Peter and Fiona Our thoughts are with you Chris and Graham. Fighting with Mavis and Ray
Plusnet, Safari 5, G5 PowerPC iMac running OSX 10.5.8, Salisbury UK : Get behind early - it gives you more time to catch up.
Well no matter what I tried I could not get access to the junction box under the panel so........the solar panel is now off the van. I used a flexible blade with a sharp end and was able to gently work it into the sikaflex joint until it came free.
Here it is:-
and here is inside the junction box on the back of the solar panel:-
I must admit to not exactly understanding what I have found. When I connect directly to the panel terminals in the above picture, it gives out just over 20V in bright sunlight but still only gives 1.5milliamps (1.5 on the 20m scale under amps).
As a double check, I connected a 5w bulb across the terminals and the voltage crashes to 0.1V and the bulb doesn't even glimmer.
So I thought I would check the diode (at least I think its a diode) that can be seen connecting the 2 terminals:-
This is the reading when connected with correct polarity:-
and this is the reading when connected with reverse polarity:-
Now, as far as I can work out the diode is working correctly. It has a resistance when connected reverse polarity (ie it allows some current flow) but does not allow current flow when correctly connected. (the 1 on the meter means infinity resistance)
Am I correct in assuming all this means the panel is fried, only wish I knew what caused it as we are so gentle with this bl**dy van.
As an aside to all the above, whilst following the cable all the way from the solar panel to the regulator, which is under the drivers seat next to the vans control box(EBL99), I found the following whilst checking and stripping all the wiring.
The wires are thick and study and do seem up to the job. The connections in the photograph below look good, completely soldered, and were covered individually with insulation tape. Then covered in more insulation tape. Furthermore, this was surrounded by the plastic cable armour that can be seen top right of the photo and hanging down on the left of the photo. This cable armour has a split down its full length so that the cable can be inserted. This was then further covered again in more insulation tape and then secured with screw clips to the underside of the van floor.
BUT, Why the short extra bit of cable ?????
and why not blue Alden cable all the way to the regulator?????
Furthermore, note when the 2nd piece of Alden cable becomes the other cable, that whoever did this job soldered the red wire to the blue and the black to the brown????? I wondered why at the regulator the black wire was routed to the + terminal. SO, it was wired correctly but.........
Is it me or does anyone else think this is shoddy workmanship??
You won't be surprised to find who fitted this solar panel...................
Brownhills.
Anyway, does anyone see a problem if I re-seal this cable back into the cable armour and secure back under the van????
Or, should I replace the red and black wire completely and make a single joint on the first connection on the left????
Is water likely to get into these joints and cause problems????
SO, WHO said this motorhoming lark would be a relaxing hobby. Step forward whilst I get my barrett .50 cal.
Why me.
However, please don't let this distract from the main solar panel issue in the preceding post. That is the main problem! Thanks.
Last edited by Triple7 on Mon Jun 01, 2009 3:55 pm; edited 3 times in total
Diagnostics over the internet is always difficult. The diode you can see is a bypass diode (not a blocking diode) and it has no purpose on a single panel installation. It isn't causing the problem as far as I can see. No I'm afraid it does look like the panel has a high resistance contact inside. This might be caused by corrosion rather than by bad handling.
Alden panels have a good reputation have you tried talking to them. I'm not sure but Brownhills may not be a good intermediary.
Before scrapping the panel is there anyone else that can look over it in case we are missing something obvious.
As too the wiring well as you say its shoddy practice and not related to th efault, but more worrying is the length of the cable compared to its thickness. Although difficult to tell from a photo it looks less than 2.5mm˛ and must be over 5 metre long, perhaps more like 8m.
______________________________________________________________ Regards Frank - - Denn wir haben nichts in die Welt gebracht; darum offenbar ist, wir werden auch nichts hinausbringen.
RIP Peter and Fiona Our thoughts are with you Chris and Graham. Fighting with Mavis and Ray
Plusnet, Safari 5, G5 PowerPC iMac running OSX 10.5.8, Salisbury UK : Get behind early - it gives you more time to catch up.
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Our thoughts are with you Chris and Graham. Fighting with Mavis and Ray 
