How To Get Solar Panel Wired ?

[Sea Dog]

Those Unisolar panels were well regarded iirc. Looking at the spec on your photo rather confirms this: although most panels now have bypass diodes, it's rare to see it noted that there's a bypass diode on every cell - a good thing when part of the panel is shaded.

 

68w isn't much, particularly when a flat mounted panel in the UK is rarely going to achieve max output. However, you should get 3-4 amps out of it in summer and even in winter you might see a bit now and then - possibly enough to keep your batteries topped up when the domestics are isolated so there's no draw on your batteries. In other words, if you leave the boat with charged batteries, they should be quite happy until you come back and will still be full when you do. If you cruise for a time too short to fully recharge your batteries, the panel will also help and on a good day may even finish the job for you. Don't expect it to do much beyond the above though - it is unlikely to keep up with even light domestic loadings on its own, and certainly not with a fridge involved.

 

With all this in mind, I'd be tempted to buy a small but decent quality solar controller, mppt type if in budget. I'd go with a 5 amp (not less, and don't spend out for much more) and disregard "upgradeablity" since if you decide you need more it's likely you'll do a complete new install rather than build on this set up.

 

Some good info above. This is another way to skin the cat, but it's what I'd be thinking about if I was in your situation. Hope that helps.

 

[NewCanalBoy]

Thank you. How much would you be spending on one ?

 

There are some that are 10 quid and some that are 150 quid - I don't think it's just manufacturer, there must be other differences.

[Sea Dog]

1 hour ago, NewCanalBoy said:

Thank you. How much would you be spending on one ?

 

There are some that are 10 quid and some that are 150 quid - I don't think it's just manufacturer, there must be other differences.

It rather depends on your budget. I like Victron stuff and a quick look at "meadotech.com" either their website or on eBay will find a couple of their 5 amp PWM controllers at 24 quid and 34 quid (Inc free delivery) the latter being their later product line with a pair of USB outputs and having an LCD information screen to help you see what's going on. You'll easily find others cheaper, probably even some of the more efficient MPPT type from "lesser" (note the quotes) manufacturers, but it's sorting out the cheap rubbish from the good value that's the issue.  I don't think it's worth spending too much with the amount of solar involved, so I'd spend the 34 quid I think.  Someone will be along shortly with a recommendation from the cheaper manufacturers I'm sure, so you'll have options without having to risk a dodgy knock-off! 

Edited July 17, 2019 by Sea Dog

[NewCanalBoy]

Right, I made a purchase and opted for the Victron 10A version with USB ports. After purchase the seller contacted me to tell me it was out of stock so gave me a free upgrade to the 20A version.

 

Having had a quick look at the instructions it says to connect to battery first, then connect to solar panel, then connect to LOAD.

 

What does it mean by 'load' ?

Edited July 20, 2019 by NewCanalBoy
.

[matty40s]

Dont worry about the LOAD function. It is designed for street lighting systems and is time programmable or light sensor switch on and off.

You could eventually use it for a night light.

The only two things you need are connect to batteries first then panels.

[NewCanalBoy]

OK thanks.

[NewCanalBoy]

So I need to get a couple of wires from the roof top down inside the cabin.

I'd rather not drill holes in the roof and remove part of the ceiling.

 

Thought about running the cables to the back of the roof, down the back of the cabin and in through the lower air vent as it's exactly where I want to be. Obviously ensuring rain water can't follow the cable in.

 

Then whilst leaning on the cabin roof trying to think of what to do realised there was a mushroom vent right in front of me. Is there any problem in dropping a couple of cables down through one of these ? It's above where I want to be so seems ideal.

[NewCanalBoy]

Ok, having just removed a couple of interior panels it's not how I expected it to be !!

 

Seems to be the vent to the engine room !!

[Alan de Enfield]

1 hour ago, NewCanalBoy said:

I'd rather not drill holes in the roof and remove part of the ceiling.

You can get a very neat and waterproof 'job' by using a 'deck-gland' (available from all good chandlers)

 

This is the one I used on my Solar cables.

 

 

[NewCanalBoy]

ooh nice.....that looks a bit better !!

Found a place where I don't have to remove the interior ceiling too.

[Alan de Enfield]

17 minutes ago, NewCanalBoy said:

ooh nice.....that looks a bit better !!

Found a place where I don't have to remove the interior ceiling too.

https://www.force4.co.uk/deck-gland.html?utm_source=google_shopping&92=11568&195=11567&gclid=Cj0KCQjwvdXpBRCoARIsAMJSKqJy-7plqkvUXWVqV3xMQTCEwFGbs6xEBRZQmc_LIUkmRA7oNgvMS5oaArNcEALw_wcB

[Sea Dog]

I went through the upright side of my slide hatch runner. It's on a vertical surface rather than horizontal and it's sheltered by the overhang of the upside down L shaped runner. Only good if that's near where you need the cables though.

 

[NewCanalBoy]

45 minutes ago, Sea Dog said:

I went through the upright side of my slide hatch runner. It's on a vertical surface rather than horizontal and it's sheltered by the overhang of the upside down L shaped runner. Only good if that's near where you need the cables though.

 

That's not a bad shout actually - would tidy things on on the roof as not a lot of cable would be visible.

Always good to have options !!

[Johny London]

Put the cable through a mushroom vent - that's what they are for! No point making more holes in the roof, no matter what you do one day it will leak. You'll have to pry down bits of ceiling board at appropriate places and fish the cable along on a rod though.

[reg]

Just one thought is your roof curved? 

If so then it's worth noting that these Unisolar panels are very low profile and if mounted on one side of a curved roof will only receive direct sun rays for a significant part of the day. This will give a pronounced drop in performance particularly in winter when the sun is low in the sky. 

If the roof is curved and it is practical to do so then sticking it down lengthways on the centreline would give a significantly better performance over mounting it on one side. 

 

Edited July 22, 2019 by reg

[NewCanalBoy]

8 hours ago, reg said:

Just one thought is your roof curved? 

If so then it's worth noting that these Unisolar panels are very low profile and if mounted on one side of a curved roof will only receive direct sun rays for a significant part of the day. This will give a pronounced drop in performance particularly in winter when the sun is low in the sky. 

If the roof is curved and it is practical to do so then sticking it down lengthways on the centreline would give a significantly better performance over mounting it on one side. 

 

Yes it's ok, it's mounted bang down the center line.

[Scholar Gypsy]

I used one of these, positioned so it is just clear of the hatch (and protected by it) when the hatch is fully open. 

PS you always need more cable than you think to join A to B internally. Don't ask how I know this.

[NewCanalBoy]

Had an interesting time today building a new battery tray in readiness for a couple of new leisure batteries.

 

Whilst studying the wiring I realised that my leisure battery has been starting the boat, and my starting battery has been supplying me lighting/pumps, etc !!

 

Not sure what has gone on here but everyday is a school day as they say !!

[Chewbacka]

56 minutes ago, NewCanalBoy said:

Had an interesting time today building a new battery tray in readiness for a couple of new leisure batteries.

 

Whilst studying the wiring I realised that my leisure battery has been starting the boat, and my starting battery has been supplying me lighting/pumps, etc !!

 

Not sure what has gone on here but everyday is a school day as they say !!

Maybe it’s just the labels are the wrong way round?

[NewCanalBoy]

41 minutes ago, Chewbacka said:

Maybe it’s just the labels are the wrong way round?

Thought this so followed positive wire back from starter motor, back to engine battery kill switch, then onto battery - which was leisure battery !! 

[WotEver]

38 minutes ago, NewCanalBoy said:

Thought this so followed positive wire back from starter motor, back to engine battery kill switch, then onto battery - which was leisure battery !! 

Isolators in starter motor feeds are a great source of failure incidentally. 

[Murflynn]

8 hours ago, NewCanalBoy said:

Thought this so followed positive wire back from starter motor, back to engine battery kill switch, then onto battery - which was leisure battery !! 

what is the difference between the batteries?

 

if it's a single leisure battery there may be no difference - both standard 110AH auto batteries, perhaps?

[NewCanalBoy]

Ones a 88 ah 680cca very much a car battery, the others an 135ah leisure battery.

[NewCanalBoy]

Well curiousity got the better of me and I temporarily wired it up. Has settled down to 2.5 A input.

 

I guess it is working and although it is not a big amount it is better than nothing - and apart from a charger unit it was FREE !!

 

 

[reg]

1 hour ago, NewCanalBoy said:

Well curiousity got the better of me and I temporarily wired it up. Has settled down to 2.5 A input.

 

I guess it is working and although it is not a big amount it is better than nothing - and apart from a charger unit it was FREE !!

 

 

Whilst you will not get a lot of output from these panels you will stand a good chance of getting some output in winter which is handy. 

Worth noting that your mppt controller is, due to bit of luck, over specified for this stand alone panel so at a later date if you choose to add higher spec panels you have a decent mppt controller available. I have 350w of mono going through my Tracer 20a controller.

Eta linked to wrong mppt so removed link. 

Edited July 23, 2019 by reg