New to solar

[Bmarler]

Yes, lol. Talking solar panels on Christmas Eve is pretty hilarious. My user experience is like this: I can measure the output from each panel since they’re on separate controllers. Like Barrie mentioned, the boat swings, I see the mast shading one panel and reducing the output by huge amounts. As the boat swings, you can watch the power output increase on the panel coming out of the shade, and reducing on the one now in the shadow of the mast. point being, I would always be at the rate of the lowest panel if I were wired in series on one controller. But since I have two controllers, one panel is putting out 30amps while the other is only at 7 or 9. The amp hours returned to the battery bank is much higher.
If my battery bank was small, maybe series wiring would be sufficient, but my bank is huge, and I want those amps.

 

[RMK818]

I installed solar on a 30 foot RV (lots of research prior to install). Ran Two 165 watt panels in series using 10 gage solar wire to a combining box (each panel fused with 10 amp fuse). Ran 6 Gage copper from combining box to MMPT controller. This prevented voltage loss (30 foot run). The MMPT will convert 24 volt to 12 volt for you and is much more efficient. Fused inverter to battery (250 Amp) and used 00 gage wire between inverter and battery. **fusing each panel protects system if one of the panels short. If you run 4 panels (100w each), connect two in parallel to create 2 arrays (array (a) and array (b) then connect the arrays in in series. This gives you more amperage at 24 volts.

 

[tpbrady]

I’m planning 400w of solar and the hardest part of the installation is getting cabling from the pilot house to the batteries in the engine room. I go right past the DC panel in the pilot house that is connected to the battery switch using 2/0 cable. Is there any reason why the battery connection can’t be at the DC panel +/-?

 

[SteveK]

I plan to connect to the DC panel as the cable from the battery is larger than needed to otherwise run to the aft battery bank from controller with panels on roof of pilothouse.

 

[twistedtree]

I’m planning 400w of solar and the hardest part of the installation is getting cabling from the pilot house to the batteries in the engine room. I go right past the DC panel in the pilot house that is connected to the battery switch using 2/0 cable. Is there any reason why the battery connection can’t be at the DC panel +/-?

No problem at all. Just use an appropriate breaker. Also consider what implication it might have on you electric metering, which will depend on the specifics of your boat. For example, if you have a meter that shows power just for the panel vs the total for your batteries, any solar production will appear as lower consumption at the panel. But that's probably not a problem on your boat?

 

[Xlantic]

I’m planning 400w of solar and the hardest part of the installation is getting cabling from the pilot house to the batteries in the engine room. I go right past the DC panel in the pilot house that is connected to the battery switch using 2/0 cable. Is there any reason why the battery connection can’t be at the DC panel +/-?

That's how mine are connected. I have two DC panels: one at the helm and one below near the engine rooms. The two DC panels are connected by thick cables, possibly 2/0. The controller connects to the helm DC panel.

I don't know if it has been mentioned but installing a circuit breaker, or at least a fuse, between the solar panels and the controller is also a good idea.

 

[Bmarler]

I’m planning 400w of solar and the hardest part of the installation is getting cabling from the pilot house to the batteries in the engine room. I go right past the DC panel in the pilot house that is connected to the battery switch using 2/0 cable. Is there any reason why the battery connection can’t be at the DC panel +/-?

this is exactly how i did it. there might be a few hundredths of a volt difference between what the mppt controllers see vs. the battery monitor (shunt). the mppt controllers are completely programmable so any difference can be made up there if needed.
tt's point of monitoring the amp draw of the electrical panel in the pilothouse isn't a concern for me, i just worry about the total amps in/out of the batteries themselves. i can see what the shunt shows, and what the panels are producing very easily.

 

[tpbrady]

Everyone,

Thanks for the comments. Sounds like it’s the way to go. Planning to use a fuse or breaker, I have both pieces available in my spares, so I’ll see what works best. I’m not worried about the DC panel meter, it doesn’t read all the loads anyway as several by pass it.

Tom