Solar Installation - Is this okay ?

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ddodg

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As I am not very electrically minded I would really appreciate if someone could cast a quick eye over my proposed plan for a soar installation.The intention is to use the solar panel only when at anchor or similar to give a smal boast to the batteries.
1) A 100 watt panel
2)A 5metre wandering lead of 6mm2 wire from panel to a bulgin deck plug
3)From bulgin deck plug a fused ( 10 amp) 6mm2 to a Victron 75/15 controller ( seems as though some question whether 6mm2 wire will fit this controller so may have to be 4mm2.) Distance from deck plug to batteries about 2metres
4)From the controller a fused ( 20 amp ) 6mm2 wire to connect to positive main master switch battery connection.Negative to main negative bus bar.

Does this all seem okay. Very open to any positive suggestions to improve.
Many thanks
David
 
I may be wrong...but on my setup (per the instructions) the negative return is from the battery to the controller and from the controller to the panel. Surely you need to complete the circuit?

The cable from controller to battery is important. It needs to be as short as possible and wide enough/with big enough fuse (1) to carry peak output, which in our case is sometimes more than the stated wattage suggests; I had to upgrade from 30A to 50A as the breaker kept tripping (2) in any case, large enough to minimise losses.
 
I can't comment on the circuitry but I think the concept is bonkers and that you'd get a much better return by using a permanently fixed system that would generate whenever it was light and obviate the need to mess around with plugging, unplugging, moving and storing panels. A simple charge controller would prevent overcharging the batteries and could be permanently connected.
I'd use semi flex panels and if space is a problem you could use 2x50w. When I first used solar panels I was a bit concerned about them being stolen as they were expensive but my fears proved unfounded and panel are (comparatively) cheap today.
 
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RJJ said:
I may be wrong...but on my setup (per the instructions) the negative return is from the battery to the controller and from the controller to the panel. Surely you need to complete the circuit?

The cable from controller to battery is important. It needs to be as short as possible and wide enough/with big enough fuse (1) to carry peak output, which in our case is sometimes more than the stated wattage suggests; I had to upgrade from 30A to 50A as the breaker kept tripping (2) in any case, large enough to minimise losses.
Click to expand...
The connection to the common earth bus would be the negative return.
 
ghostlymoron said:
I can't comment on the circuitry but I think the concept is bonkers and that you'd get a much better return by using a permanently fixed system that would generate whenever it was light and obviate the need to mess around with plugging, unplugging, moving and storing panels. A simple charge controller would prevent overcharging the batteries and could be permanently connected.
I'd use semi flex panels and if space is a problem you could use 2x50w. When I first used solar panels I was a bit concerned about them being stolen as they were expensive but my fears proved unfounded and panel are (comparatively) cheap today.
Click to expand...
Why is it bonkers? @ddodg only wants to use the solar panel when at anchor. There are lots of 'solar blankets' sold specifically for that purpose.

I'm looking to add solar power next summer and the thought of being able to pop a solar blanket on the foredeck when at anchor in addition to fixed panels really appeals. My 200 watts can become 400 for a few hours.
 
Agree, we don't all want our boats to look like shanty towns with stuff bolted all over the place. I put my solar out when I'm at anchor but I'm quite happy to put it away when I leave.
 
I suppose it depends on how you use your boat. When I'm over at mine, I tend to only be anchored in the evening and night - ie when the sun is low. The potential power generation occurs is at its greatest during the midday hours when I'm sailing so I like to harvest it as much as possible. I only have a small panel.
 
Sandy said:
Why is it bonkers? @ddodg only wants to use the solar panel when at anchor. There are lots of 'solar blankets' sold specifically for that purpose.

I'm looking to add solar power next summer and the thought of being able to pop a solar blanket on the foredeck when at anchor in addition to fixed panels really appeals. My 200 watts can become 400 for a few hours.
Click to expand...
I've never heard of a solar blanket - what is it?
 
That is very similar to our setup, we have an 80 watt panel that we leave out on deck, usually after a weekends use as our electric consumption is pretty minimal. So long as your wiring is large enough to handle the currents and minimise any voltage drops over the lengths mentioned there should be no problem.
 
Circuitry sounds right except you don't need a fuse between the solar panel and the controller. As for permanent or temporary that is up to OP and his options for mounting solar panel. I would go for small panel permanent with the option for larger for use when camping. Problem being storing the large panel when not in use. ol'will
 
A minor point, but I think I would favour these over Bulgin for new installations: IP67 Waterproof Panel Mount Connectors (12V,20A) | 12 Volt Planet

These are made by a company called CNlinko, have a smaller footprint than Buglin, and are cheaper. Because Bulgin connectors have quite a fine thread, I have found them occasionally difficult to fasten or prone to misthreading - the CNlinko requires only about a full turn and I'd expect them to slot into place more readily. I've not used them, but looked them up after a couple of people recommenced then on another thread.

These are also available from eBay and AliExpress, who may be cheaper but with longer lead times.
 
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