How do I connect 5 solar panels?

[Santa]

I am going to be doing a slightly modified version of Will's blueprint. https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

I have (4) 100 watt polycrystalline panels, and (1) 100 watt monocrystalline suitcase panel. The specs on both types are very close to being the same. I want to have the option of moving the suitcase panel in and out of a vehicle for sun, so stealth can be achieved when necessary. Since the MC4 Y branch (1 to 4 parallel connector) is only for 4 panels, how would I connect the 5th one? Thank you for your help.

 

[MisterSandals]

Since the MC4 Y branch (1 to 4 parallel connector) is only for 4 panels, how would I connect the 5th one?

You can add a MC4 Y branch (1 to 2 parallel connector) to your 1 to 4 connector when you want to add your 5th panel. You could actually add this 1 to 2 connector anywhere between the panel(s) and your SCC.

 

[Santa]

You can add a MC4 Y branch (1 to 2 parallel connector) to your 1 to 4 connector when you want to add your 5th panel. You could actually add this 1 to 2 connector anywhere between the panel(s) and your SCC.

Thank you! Some things are obvious to some people, lol. ;-p That's why brainstorming on the forum is so great!

 

[MisterSandals]

This is a little creepy this time of the year...

 

[Santa]

This is a little creepy this time of the year...

LMAO! Thank you for the laugh! I needed that, I mean, ho, ho, ho!

 

[Deleted member 783]

She knows when you are sleeping.. ?

 

[Santa]

Thanks New Mexico Will. LOL

 

[Santa]

You can add a MC4 Y branch (1 to 2 parallel connector) to your 1 to 4 connector when you want to add your 5th panel. You could actually add this 1 to 2 connector anywhere between the panel(s) and your SCC.

BTW, wouldn't there be a drop in voltage to have 2 branch connectors?

 

[Deleted member 783]

Could you use these and just not use one?

 

[Santa]

Could you use these and just not use one?

View attachment 3789

Thanks Will! I searched for 5...but didn't see any. I just didn't ask the right search question! Is there going to be power loss from the extra connection that's not being used? (I can't add any more panels bc of the charge controller limits.)

 

[DThames]

BTW, wouldn't there be a drop in voltage to have 2 branch connectors?

Ideally, the fewer connections the better. But if they are good connectors, not a big problem with connecting them(the connectors) in series. A tiny voltage drop across a connection is not a problem unless there is so much current that there is then enough heat across that connection that the heating is a problem.

 

[DThames]

Thanks Will! I searched for 5...but didn't see any. I just didn't ask the right search question! Is there going to be power loss from the extra connection that's not being used? (I can't add any more panels bc of the charge controller limits.)

Just keep water out of the unused connections. No loss from an unused connection.

 

[MisterSandals]

I would consider the location of where you would put the 1 to 6 connector and see if that is a convenient location to hook up your carry out panel. Since its all parallel, you can add your 5th (carry out) panel connection anywhere. I would see if there is a convenient place to add (the earlier discussed) 1 to 2 connector that does not require you to get up on the roof.

Otherwise the 1 to 6 is a great idea. Plug up the unused ports to keep them clean.

 

[Santa]

all great ideas and things to consider! Thank you!

 

[Deleted member 783]

Dust caps for the unused one. I have 4 panels in parallel and I doubled up on branch connectors to make that happen-no issues.

 

[Santa]

Dust caps for the unused one. I have 4 panels in parallel and I doubled up on branch connectors to make that happen-no issues.

View attachment 3790

Who knew?

 

[Deleted member 783]

Who knew?

Not me, I just did a search and there they were. I've alway said that the most important part of any DIY project is just knowing what products are out there.

 

[PHoganDive]

FYI, Combining panels in parrallel that way can be dangerous when the panel count goes over 3 or so. The reason is if any panel develops a problem, it can be back-fed the combined current from all the other parrallel panels, which can have more total current than the wire and panel can handle, posing a fire risk. That's why combiner boxes always individually fuse or circuit breaker each string.

 

[Deleted member 783]

FYI, Combining panels in parrallel that way can be dangerous when the panel count goes over 3 or so. The reason is if any panel develops a problem, it can be back-fed the combined current from all the other parrallel panels, which can have more total current than the wire and panel can handle, posing a fire risk. That's why combiner boxes always individually fuse or circuit breaker each string.

Wouldn't the panels' blocking diodes protect against this?

 

[Santa]

FYI, Combining panels in parrallel that way can be dangerous when the panel count goes over 3 or so. The reason is if any panel develops a problem, it can be back-fed the combined current from all the other parrallel panels, which can have more total current than the wire and panel can handle, posing a fire risk. That's why combiner boxes always individually fuse or circuit breaker each string.

Will said 4 panels would work. I was just thinking of throwing the suitcase in, since I already had it and it would be slightly under the controller's capability. If I am wrong, please let me know.