Repurpose Solar panel for garden lighting.

[TrevandJenny]

New 120w solar panel fitted on our MH and working well, Thanks again to Wildebus, Trevskoda and others for advice, Opinions please.
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What to do with the old one, Heres a thought
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I could fit the old Auto sleepers 80w panel on my workshop roof, I am at present awaiting a delivery of a basic controller, Reading online and listings on this forum regarding voltage drop in cable. The cable on the panel is 4mm joined to an 2.5mm extension cable going to the Sargent panel, that I assume was applied when MH was built looks to thin for me.
.
I assume the 2.5mm cable should also be 4mm. I have found a supplier with 4.5mm strand twin core flat cable its neater to fit. Or is this to big for use? or should I use 2 separate 4mm cables??.
.
When up and running it will power a 68amh AGM battery that will in theory run the 12v lights in our back garden, I hope

 

[jagmanx]

The other option is to run a 240v cable amd use a 240v ac to 12v dc converter (of suitable ratimg
Or indeed just run 12v from the house.
Seems a waste and cost of a battery and controller to me.
Depends what suits ?
The 240v to 12v units are very cheap !
And 12v is safe !
With 12 v available you can also charge your phone/tablet

 

[Mr and Mrs Tupcox]

My daughter has a field and stable for children's horse they wanted a 240 supply putting in after many quotations of around 4k.
We fitted 2x 150 panels a mppt controller and 2x110amph batteries. And 2000w inverter..
About 1k .
They now have good lighting and a 240 socket ..
Panels angled to winter sun.
Works fine..

 

[jagmanx]

My daughter has a field and stable for children's horse they wanted a 240 supply putting in after many quotations of around 4k.
We fitted 2x 150 panels a mppt controller and 2x110amph batteries. And 2000w inverter..
About 1k .
They now have good lighting and a 240 socket ..
Panels angled to winter sun.
Works fine..

yes but all down to distance !
Indeed a perfect solution
I will add "Horses for courses"

 

[jagmanx]

there are also many "readymade lighting solutions"
We use 2 here in Thailand
Solar panel about 12 in by 15
Cable 5m
LED Floodight 10 in by 8in with movement sensor and built in battery
Loadsalight about £20
Any need for 240V ac is another dimension

 

[wildebus]

New 120w solar panel fitted on our MH and working well, Thanks again to Wildebus, Trevskoda and others for advice, Opinions please.
.
What to do with the old one, Heres a thought
.
I could fit the old Auto sleepers 80w panel on my workshop roof, I am at present awaiting a delivery of a basic controller, Reading online and listings on this forum regarding voltage drop in cable. The cable on the panel is 4mm joined to an 2.5mm extension cable going to the Sargent panel, that I assume was applied when MH was built looks to thin for me.
.
I assume the 2.5mm cable should also be 4mm. I have found a supplier with 4.5mm strand twin core flat cable its neater to fit. Or is this to big for use? or should I use 2 separate 4mm cables??.
.
When up and running it will power a 68amh AGM battery that will in theory run the 12v lights in our back garden, I hope

In terms of cost-effectiveness, Jagmanx makes a good point (the same is also true of Solar panels on a motorhome for people who only stop at full-service campsites).

But if the kit is there and spare though, why not use it
Cable gauge .... for an 80W panel, you could easily get away with 1.0mm2 cable in truth. Thicker the better to avoid losses, though, so I would go a bit thicker but definately wouldn't bother going above 2.5mm2. There really is no need. And if I happened to have 1.5mm2 knocking around I would use that for sure.
Given this is a stationary installation, you don't need to concern yourself with vibration worries or the like, so if it were me and I wanted to do this as safely AND as cheaply as possible, I'd likely compare prices of 2.5mm solar cable with twin-core 2mm cable (such as this - https://simplysplitcharge.co.uk/Cables/Twin-Core-Cable?product_id=760) and get the cheapest.

You should not skimp on the safety side of course in terms of fuse protection - get a basic fuse holder and 10A fuse to protect the install.
You could get something like this - https://amzn.to/3FTBEk8. 4 independant fuses .. use one for the incoming solar feed TO the battery, and others FROM the battery for the lighting connection and maybe another to let you add in a USB socket for handy emergency phone charging?

 

[TrevandJenny]

The other option is to run a 240v cable amd use a 240v ac to 12v dc converter (of suitable ratimg
Or indeed just run 12v from the house.
Seems a waste and cost of a battery and controller to me.
Depends what suits ?
The 240v to 12v units are very cheap !
And 12v is safe !
With 12 v available you can also charge your phone/tablet

The panel and battery were both surplus to requirements, I bought a cheepo controller as if the project did not work well I was only out a few quid

 

[jagmanx]

Yes the only cost being the controller makes it a plan but the battery will not last forever !
However a nice project and it could easily be redirected with a 240V t0 12V unit
I really like the idea of 12v LED lighting...just offering an alternative power source

 

[wildebus]

Yes the only cost being the controller makes it a plan but the battery will not last forever !
However a nice project and it could easily be redirected with a 240V t0 12V unit
I really like the idea of 12v LED lighting...just offering an alternative power source

By the time the battery is total scrap, there is a fair chance another one will be available to take its place. maybe the starter battery from the van will be past its best? or a old leisure battery from the van (or someone elses van?).
I still have my old AGM batteries from my Motorhome that were fitted when I bought it and past it (10 years old!) - but one of them is still good enough for light loads such as 12V lighting. I have some panels that sit on a shed roof and supplement the motorhome solar when at home but could also divert to use for outdoor garden lighting (now Storm Arwen took away two very large trees, I will have a lot more sun in the garden!)

 

[TrevandJenny]

In terms of cost-effectiveness, Jagmanx makes a good point (the same is also true of Solar panels on a motorhome for people who only stop at full-service campsites).

But if the kit is there and spare though, why not use it
Cable gauge .... for an 80W panel, you could easily get away with 1.0mm2 cable in truth. Thicker the better to avoid losses, though, so I would go a bit thicker but definately wouldn't bother going above 2.5mm2. There really is no need. And if I happened to have 1.5mm2 knocking around I would use that for sure.
Given this is a stationary installation, you don't need to concern yourself with vibration worries or the like, so if it were me and I wanted to do this as safely AND as cheaply as possible, I'd likely compare prices of 2.5mm solar cable with twin-core 2mm cable (such as this - https://simplysplitcharge.co.uk/Cables/Twin-Core-Cable?product_id=760) and get the cheapest.

You should not skimp on the safety side of course in terms of fuse protection - get a basic fuse holder and 10A fuse to protect the install.
You could get something like this - https://amzn.to/3FTBEk8. 4 independant fuses .. use one for the incoming solar feed TO the battery, and others FROM the battery for the lighting connection and maybe another to let you add in a USB socket for handy emergency phone charging?

Many thanks, Now I understand why a smaller than 4mm was used when MH was made, Ive ordered as suggested as well as a fuse holder. Thanks.

 

[Geek]

For any cables running outdoors, make sure they are well sealed against moisture. I use heatshrink over each connection, but that isn't enough to stop the cables getting damp inside and corroding the copper inside.

 

[CriftinsCampers]

I re used my redundant 240w panel by hanging it on the side of my garage. It’s hinged at the top so I can adjust it to better face the sun at a right angle in the winter.

It’s wired up using some spare T&E cable to a 20A Mppt controller.
I use it via an inverter to run a small fridge and also keep various vehicle and other spare batteries trickle charged all year around.

Picture in the link below

Keith Alexander on Instagram: "One 325w panel and five lengths of Unistrut ready for fitting a deck to #exambulance"

8 likes, 4 comments - criftins.campers on July 24, 2020: "One 325w panel and five lengths of Unistrut ready for fitting a deck to #exambulance".

www.instagram.com

 

[TrevandJenny]

Many thanks, Now I understand why a smaller than 4mm was used when MH was made, Ive ordered as suggested as well as a fuse holder. Thanks.

First day of near reasonable weather today so fitted panel to workshop roof well sealed screw holes, placed AGM battery on top shelf of racking inside, cable from panel to controller 70cm from controller to battery 40cm. All seems to be working fine yet to try out garden lights as awaiting delivery of photocell switch and inline fuse. Thanks for everyones advice.

 

[Molly 3]

Sounds like the birth of a DIY power wall system .