Fixing a non-working PV module

paulstamser

Hi,

I have a BP 10 watt polycrystal PV panel on a garage for charging a car battery that has stopped working. I tested it at the wires coming out of the panel and it seems to be the panel itself. Bad news, as on the outside it looks brand new. Never dropped or otherwise damaged.

Is it ever possible to fix one of these things? The wires come out of a little black box glued to the back of the panel. If I push on this box, one time I got it to work for a moment. I've had it for a few years so I doubt the warranty is still good, but I still have to dig the paperwork out.

Thanks!

niel

Re: Fixing a non-working PV module

it sounds as if an internal wire has broken and it may prove difficult or nearly impossible for you to fix it.

BB.

Re: Fixing a non-working PV module

If there is still a label and serial number on the panel--I would contact BP and see what they say... There should be a long warranty on their product.

-Bill

paulstamser

Re: Fixing a non-working PV module

I figured it would be difficult or impossible to fix myself.

But there is a sticker with serial number still on the module, so perhaps contacting BP would be my best option. Possibly some of the warranty is left.

Already I feel naked without it, as I don't drive much and my car sits for long spells without operating and charging the battery via the alternator.

It almost seemed like this malfunctioning module was actually draining my car battery. Is that likely to happen?

Thanks!

Windsun

Re: Fixing a non-working PV module

BB. wrote: »

If there is still a label and serial number on the panel--I would contact BP and see what they say... There should be long warranty on their product.

-Bill

On most larger panels - 40 watts and up - the typical warranties have been 20-25 years for over a decade now.

However, for many smaller panels, especially in the 1 to 10 watt range, warranty can range anywhere from 1 to 10 years, with many older panels being in the 1 to 5 year range.

niel

Re: Fixing a non-working PV module

paulstamser wrote: »

It almost seemed like this malfunctioning module was actually draining my car battery. Is that likely to happen?

Thanks!

that could very well have been the case even before your wire problem occured if there wasn't a blocking diode present either in the pv itself or external to it.

JESSICA

Re: Fixing a non-working PV module

paulstamser wrote: »

Possibly some of the warranty is left.
Thanks!

Do you remember how much you paid for the panel?
Even if there is a warranty that may cover the repair, do you know how much will you have to pay just to send the panel to the factory?

Perhaps, (I repeat: Perhaps), it is more cost-effective to buy a new one than to repair the old one.

mike95490

Re: Fixing a non-working PV module

VW ships a 5W module on the dashboard of each car going overseas, to keep the battery topped off. These sometimes show up in large batches on ePay for a reasonable cost. Plugs into the lighter socket.

jacobs

Re: Fixing a non-working PV module

I had three 20+ year old Arco M53 panels that quit working. Upon inspection, I discovered the factory installed bypass diodes were shorted. I removed the diodes and the panels performed like new.

niel

Re: Fixing a non-working PV module

do not confuse a blocking diode with a bypass diode as they perform different functions.

jacobs

Re: Fixing a non-working PV module

niel wrote: »

do not confuse a blocking diode with a bypass diode as they perform different functions.

You are correct, a bypass and a blocking diode are totally different. A bypass diode is installed between the positive and negative terminals of the panel. IF the bypass diode shorts out, the panel will thus appear dead with no voltage at the terminals. Remove the bypass diode and viola, the panel works again.

Bypass diodes are only needed in high voltage installations and then only if shading is possible to occur.

73

paulstamser

Re: Fixing a non-working PV module

Update on broken BP 10 watt garage panel:

I examined this BP 10 watt module closer. I can definately make it work by pressing and pushing on the little cover and the wires that come out of it, but as soon as I let up on the pressure it quits.

Then I noticed that the little cover was not glued on very well, so being the curious type, I used a razor blade to cut it free to remove it.

Cover off, the problem was instantly clear. Moisture had gotten under the little cover and corroded and broke the positive wire connection where it is soldered to a VERY short braided wire tab coming out of the panel. The original BP factory attempt to seal the soldered connection was very poorly done, inept, and totally failed. Some silicone had been squirted behind the cover, but there was an wide open pathway that allowed moisture to enter, collect, persist, and over time corrode and break the positive soldered connection, which itself was a very tenuous and weak affair to begin with. The design itself is poor and the worksmanship shoddy. I can see why they only give a 1 to 5 year warranty on these smaller panels as they are "guaranteed" to fail.

So much for BP quality control on their 10 watt panel line.

Anyway, an expert solderer might be able to fix this thing by re-soldering the lead wire back onto the short braided wire tab coming out of the panel. Unfortunately I am not a very good solderer and don't know anyone who is. I often have trouble making solder stick, but I feel compelled to attempt fixing this thing. The panel itself still works and I'd hate to junk it and buy a new one when that shouldn't be necessary.

I'm low impact and want to stay that way!

Any tips/advice about soldering this thing? All I have for tools is a small 12 volt Radio Shack soldering iron and a small butane torch. The latter would no doubt fry this thing, so the 12 volt iron is my best bet. The little braided wire coming out of the panels is VERY short so I'll have very little to work with. I have electrical solder but do I need to get anything else?

I'd really like to fix this thing. It isn't just the money to buy a new one (which would NOT be a BP), but the principle of the thing that junking an otherwise working panel due to a mere corroded wire would almost be criminal.

Thanks!

PS: As I recall, this panel cost about $100 when new, but I haven't been able to locate the original invoice or paperwork yet. It's here somewhere...

BB.

Re: Fixing a non-working PV module

Either use rosin core/paste and eutectic solder, or look for "no clean solder paste/liquid".

Don't use any other types of flux--you will get corrosion problems that will just ruin the panel in months.

After soldering, if needed, you can try denatured alcohol to clean out the repair--and leave the panel in full sun for a day to drive out the alcohol and water before sealing.

-Bill

mike95490

Re: Fixing a non-working PV module

Soldering repair
If it was I, I would get some rosin core electrical solder. Not acid core plumbing solder. NOT Lead FREE - (too high of melting point). Maybe an old electronics shop still has 63/37 lead tin solder. (60/40 works too) Clean, prep and pre-tin your new wire. Does the other wire look ok, or will it need repair too? use some small tweezers, pick all the old corrosion out that you can, and then, quickly, with a hot iron (maybe heat the 12V iron just a bit with the torch) reflow and re-tin the braid on the panel.
It's better to have the iron hotter, and use it less, than a too cool iron, and slowly BBQ the whole panel while getting it up to soldering temp. Let things cool after this first step, you don't want to crack the glass, or have the braid fall off internally. position the fresh wire and the braid, and solder them both together.
If you can locate any ROSIN paste or liquid flux, a drop off the tip of a toothpick, is the right size. It both bubbles away the oxides, and helps conduct heat into the joint faster than a bare/dry iron.

--

This mission, while greatly rewarding, is not officially sanctioned by your electrical providers. If you are captured, you will be remembered for the revolution.

paulstamser

Re: Fixing a non-working PV module

Thanks both for the excellent advice. I'll see what kind of solder I have on hand and if I need to make a trip to the hardware store.

Even if I do have rosin core electrical solder, is there any advantage to get a seperate can/bottle of paste or liquid flux?

I'm going to attempt fixing this panel and I appreciate the input very much.

BB.

Re: Fixing a non-working PV module

Probably not--other than a bit more cleaning when you add the liquid/paste flux...

-Bill

paulstamser

Re: Fixing a non-working PV module

Thanks BB.

The other (neg.) wire connection still appears sound. It was not subject to the same moisture and corrosion.

I have two coils of rosin core electrical solder:

1) 60/40 lead/tin
2) 60/40 tin/lead

Which is better for this type of job?

BB.

Re: Fixing a non-working PV module

You want the 60/40 Tin/Lead (the other may also be 60/40 Tin/Lead--the label may be a typo). That should be the lowest temperature solder. To check, try melting both with a cool iron (one that has just been plugged in and starts heating--the one that melts first is the one you will want--or you may find both melt at the same same time--meaning they are both the same alloy/mix). From reading this--I did not realize that 60/40 T/L was chosen because it provides a thicker coating on wires... Learn something new every day. :cool:

60/40 T/L is very near the eutectic mix of 63/37 (goes from liquid directly to solid without a "mushy" stage where wiggling the joint while cooling creates a poor joint).

0Bill

paulstamser

Re: Fixing a non-working PV module

Yesterday I was cleaning off the wires to be soldered on this broke BP panel. It seems rather doubtful that I'll be able to fix it. The remaining wire tab is so darn short and there's silicone embedded in and around it. Plus it's tight against the panel itself. I'm tempted to cut around it but don't dare.

The negative wire which initially looked okay is also corroded, and right up where it enters the panel. Not good. I'll leave it anyway.

Such a shame than an otherwise good panel may be destined for the junk heap.

Thanks for listening to this tale of woe...

paulstamser

Re: Fixing a non-working PV module

Update on broken BP module:

Well, I managed to solder the broken wire coming out of the panel. However, while I was straightening the wires after that the already weak negative wire broke off. This one is right at the panel surface and even shorter to solder onto. Almost nothing at all.

I wonder how much I can cut into the plastic panel backing and if there's any more wire under there to free up?

This is just experimenting now because I already bought a replacement and mounted it on my garage.