Universal solar connector cables? 🤔

[Fergus]

Hi folks, I don't seem to be getting a charge from my roof-mounted solar panel any longer, but with nothing obvious in the whole setup to explain why. I'm considering buying a new one and simply gluing it on top of the old one, but does anyone know if male-female and female-male connectors (pic attached) are universal, i.e. can I buy a different brand of panel (same wattage) and simply connect its output cables to the cables that go into the van and connect to the split charger/batteries?
Thanks,
Fergus

 

[Boris7]

Think you need to test your existing panel first (easy done) then depending on outcome trace back to the battery

 

[Robmac]

Presumably your new panel will come with connectors attached anyway, In which case you can simply connect to the old extension wires? But IF the problem is with the old panel I would remove it anyway. Is it a flexi panel? I intend to remove mine with fishing line used as a sort of cheese wire.

If you suspect the connectors you have are faulty you should be able to check with a voltmeter.

 

[Boris7]

An easy option would be to find someone with a portable panel and plug that into the existing cables

 

[Fisherman]

Hi folks, I don't seem to be getting a charge from my roof-mounted solar panel any longer, but with nothing obvious in the whole setup to explain why. I'm considering buying a new one and simply gluing it on top of the old one, but does anyone know if male-female and female-male connectors (pic attached) are universal, i.e. can I buy a different brand of panel (same wattage) and simply connect its output cables to the cables that go into the van and connect to the split charger/batteries?
Thanks,
Fergus

The MC4 connectors you have are standardised, and you can use the same connectors made by different manufacturers. I would secure them to the roof using adhesive, when using them.
But before replacing your panel simply disconnect the panel then use a multi meter to check for voltage during daylight from the panel. You should get a reading at least 5v above the 12vDC used in your van. If you don’t then your panel does require replacing.
Surface mounted panels tend not to last as long as rigid panels, I would replace your existing surface mounted panel with a rigid panel if this is possible. You don’t need to use mechanical fixings, you can do so using an appropriate adhesive, and following their instructions for use carefully.

If the panel voltage is ok then then check the voltage at your solar controller input. The voltage should be almost the same here. If there is no reading ensure that your connections on the roof are sound.

If the voltage at the solar controller input is ok you may have a faulty controller, or its internal fuse may have blown.

 

[wildebus]

When/if you get any MC4 connectors bear in mind that while one is marked with a red band and a "+" symbol, and the other has no band and has a "-" symbol on it, the connectors are NOT specifically +ve and -ve, and either connector could be a +ve OR a -ve depending on its position in the wiring.
Pointing this out as it is very easy to get mixed up with solar cable wiring as it disappears into the roof and reappears elsewhere ....
This may be of interest.... https://wildebus.com/posts/solar-panels-connections/

 

[Fergus]

The MC4 connectors you have are standardised, and you can use the same connectors made by different manufacturers. I would secure them to the roof using adhesive, when using them.
But before replacing your panel simply disconnect the panel then use a multi meter to check for voltage during daylight from the panel. You should get a reading at least 5v above the 12vDC used in your van. If you don’t then your panel does require replacing.
Surface mounted panels tend not to last as long as rigid panels, I would replace your existing surface mounted panel with a rigid panel if this is possible. You don’t need to use mechanical fixings, you can do so using an appropriate adhesive, and following their instructions for use carefully.

If the panel voltage is ok then then check the voltage at your solar controller input. The voltage should be almost the same here. If there is no reading ensure that your connections on the roof are sound.

If the voltage at the solar controller input is ok you may have a faulty controller, or its internal fuse may have blown.

Thanks, Fisherman - really useful. Yes, I checked the panel on it's own with a multimeter but got no reading at all.
Cheers

 

[Fergus]

When/if you get any MC4 connectors bear in mind that while one is marked with a red band and a "+" symbol, and the other has no band and has a "-" symbol on it, the connectors are NOT specifically +ve and -ve, and either connector could be a +ve OR a -ve depending on its position in the wiring.
Pointing this out as it is very easy to get mixed up with solar cable wiring as it disappears into the roof and reappears elsewhere ....
This may be of interest.... https://wildebus.com/posts/solar-panels-connections/

Thanks, wildebus - will definitely keep that in mind!
Cheers

 

[Pudsey Bear]

Having fitted a few panels over the years I never do any connections on the roof, I site the roof entry gland above a locker or wardrobe and connect in there and I use ordinary chocolate blocks as the MC4 connectors are a pain without the correct tools and as David mentions there is zero guarantee how they are actually connected.

 

[davef]

I added a 50w panel to my existing 75w yesterday. You cannot get the MC4 connectors through the cable gland, so they seem a bit pointless to me. I cut them off and fed the cable through the gland into a side locker where I used quick connectors to lengthen the wires to the controller. Seems to me the fewer connections outside subject to weather the better.

 

[Pudsey Bear]

They mostly come without any connectors fitted so not normally an issue.

 

[Fisherman]

T

I added a 50w panel to my existing 75w yesterday. You cannot get the MC4 connectors through the cable gland, so they seem a bit pointless to me. I cut them off and fed the cable through the gland into a side locker where I used quick connectors to lengthen the wires to the controller. Seems to me the fewer connections outside subject to weather the better.

it all depends on your solar array.
I have four panels wired in parallel so joints on the roof are not avoidable.
I had to use a two way connector from the two rear panels, and a three way connector from the front panels back to the controller.
But I try to position them under the panels.
I also put some sikaflex around the joint for additional water integrity.
But MC4 connectors are waterproof and to date I have had no issues with them.
People have external tv aerials with water proof connectors, with no issues.
But obviously having no external connections would be ideal.

 

[Pudsey Bear]

Nice install that Bill.

 

[wildebus]

MC4 connectors are usually very robust and reliable and I tend to keep them in place as they are waterproof and allow simple servicing of panels if any work needs to be carried out.
Right now I have 9 separate panels on the motorhome roof, all connected using MC4 connectors on the panels plus a bunch of MC4 Combiners.
You do have to make sure they are pushed together fully (listen for the 'click') but once installed, they really are a 'fit & forget' system but one that also allows for maintenance.

As Bill says, connections on the roof side are unavoidable if you have multiple panels so need some kind of connections, so why not use the one already fitted?
If removing and using block connectors, I would suggest looking at the WAGO Lever Connectors rather than the old-fashioned 'choc bloc' strips.

 

[Pudsey Bear]

Correct as ever David, none of mine ever came with them, I did buy them for my first panel fitting but found them to be a faff and terminated inside the van, I use pin connectors into the choco blocks I have tried the Wago type connectors and they are really good.

 

[wildebus]

Correct as ever David, none of mine ever came with them, I did buy them for my first panel fitting but found them to be a faff and terminated inside the van, I use pin connectors into the choco blocks I have tried the Wago type connectors and they are really good.

fairly unusual they didn't come with them as they are very much a standard.
Some of the smaller Victron panels sometimes don't with connectors - or even cables! Actually handy as you can then add cables the length you need, so cloud and siver lining there ....

Thinking on, the last MH solar install I did (on a Malibu), the van came with a Truma Solar Panel and that had a different connector to the MC4s.
Can't recall exactly what it was, but it was very nice actually and the cable used was a double insulated pair with one common outer core (similar to one Fisherman Bill has on his Rapido into the roof). Had to splice into that to add MC4s to allow another 3 panels to be added (and then another 2 more a couple of weeks later).
Like so many things with Motorhomes and Electrics, there are often lots of different but perfectly good ways to get to the same result