Small DIY Shed Install for lights etc

[killersheep34]

Hi,

I'm new to solar tech, but have a general basic understanding of requirements and wish to just dabble with it a little.

Here's what I want to do.

Basically, a mini shed install to power some low wattage diy built lights scattered around a nice area of our garden to brighten it up a bit and ditch / replace the rubbish solar lights bought from B&M / homesense etc. I will be using Edison 1w led bulbs, and a few other 12v 1w bulbs, and I would say a maximum of say 15w to be used for about 4 hours a night (on a timer).

I am looking at purchasing a Renogy 50w Solar kit as per attached

https://uk.renogy.com/50-watt-12v-monocrystalline-starter-kit/

This comes with a 10amp charge controller. Will this be sufficient? I'm calculating just over 1amp consumed by my load.
Also comes with a 50w solar panel. Is this too much? Could I get away with a 30w? I would say we get 50% cloudy days, decent sun for 5-7 hours a day.
I was looking at getting a 12v 14ah sealed lead acid deep cycle battery. Is this too much? Could I get away with a smaller one?

I wanted to buy from an established brand and note there are a lot of cheaper Chinese units on Amazon, but would rather buy quality to save from any accidental fires!

Also, with regards to the battery, is it OK on a shelf in the shed? I am based in UK, SW. Our winters are fairly cold (down to -5 C) and summers can have odd hot days (35C). Should I be looking at purchasing additional battery monitoring equipment?

I'd also like to point out that the lights I'd like to install are probably about 7m away from the shed. Am I ok running 12v cable over that distance with approx max 2a running through it, and what AWG should I be using?

Any help is greatly appreciated!

Kind Regards.

 

[45North]

Sounds good!
My kind of project.
Learn from my mistakes!

 

[45North]

Your plan sounds good to me as written.
Long as you stick to 12v lights and skip the Inverter you should be fine (thus avoiding conversion and stand-by losses)
50 W panel and 14Ah battery should do fine. You're a little north of me so you may want to tilt your panel more in winter when the sun is low. But I don't imagine you get much snow cover to worry about, if any.
The SLA battery should be fine in the shed at those temps (it's only Lithiums you have to worry about charging below freezing)

I'd add some battery monitoring just for interest sake. But that's just me being nerdy. Your controller should do this.

I wouldn't fuss about the wiring too much - it's very low power so whatever you have on hand should be fine, even speaker wire. But if you're concerned about sunlight UV damage to the insulation you could get Landscaping wire specifically for this purpose.

I'd suggest a little 12v fuse block. It makes a nice central point for your wiring.

https://www.amazon.ca/Kohree-Standard-Indicator-Waterpoof-Protection/dp/B07S99H25W/ref=sr_1_6?dchild=1&keywords=12v+load+panel&qid=1618417687&s=electronics&sr=1-6

Your 10A controller should be adequate. I'm not familiar with that particular one but some have load output timers built in but with max load limit you should check. (With just a few LED's you may be OK. It's when you start running bigger loads like Inverters that you have to hook them directly to the battery, which obviously then can't be controlled by the built-in load timer)

Looks like an interesting project! Please keep us posted.

 

[killersheep34]

Thank you for your reply. I'm glad I'm heading in the right direction.

I have no intention of using an inverter, it's just a bit of fun really. I may run some 3v devices off of it, like some of the battery operated lights we use in the garden too, but I can't imagine these draw much current.

The fuse box is a definite, thanks for reminding me. I assume I fuse the solar panel, battery and loads all individually?

Are there any other basic solar controllers you would recommend?

I will definitely keep all posted.

 

[killersheep34]

Also, what sort of battery monitoring would you suggest?

I was thinking an external voltmeter display and some kind of temperature sensor that I could install on the window of my shed so I can see if without going into the shed?

Many thanks.

 

[45North]

The Renogy Wanderer in your starter kit should be fine. I'd opt for the optional Bluetooth plug-in monitor just for fun because I like data.
It's an inexpensive PWM type rather than the more efficient (and expensive) MPPT type but that should be fine for your purposes. That's what I had on my little system. (I've since given it away to a friend with a boat and a solar-powered bilge pump but that's another story)
I notice the Wanderer also has load output terminals so that should be good for timing your lights if your power's not too high.

Fuses: I didn't bother much with fuses - figuring the power was so low what could go wrong? Sacrilege, I know! But I suppose you could add some if you want to feel safer (others on here could tell you better than I)

Wiring: depending on the layout of your yard:

• you may want to run every light back to the shed, let's call it Star layout.
• otherwise, you may want more of a Trunk layout with a few main lines and branches off it. You'll have to think about how best to connect them. I've seen special Landscape wiring which has branches that pierce the main wire. Seems like that could work but I haven't tried them and I don't know if they're waterproof for outdoor use.
  • These are called T-taps
    • https://www.amazon.ca/gp/product/B0...c&pd_rd_w=wTh0a&pd_rd_wg=0LDot&ref_=pd_gw_unk
• I use lever connectors for small projects but these are not waterproof.

 

[killersheep34]

Hi. It's me again.

I am slowly collating all my bits required for this install. Now just down to picking the right sort of battery. Do I need a deep cycle battery? What is the benefit of this?

Also, do I need to worry about grounding my system, and if so, how should I go about doing this? Or will a 10a fuse on both battery terminals be OK?

Many thanks.

 

[DThames]

If you are getting a lead acid, yes a deep cycle type. A better solution would be a LiFePo4 battery similar to this one.

 

[killersheep34]

Hi,

Thank you. I'm not sure about LiFePo4 myself as I feel they are a little more unstable then lead and I don't really want to cause any fires if I can help it!?

What about the earthing situation, is that needed? Bare in mind my load is only about 15-20w, all low voltage 12v and I will not be using an inverter, however, I understand that a panel on a roof of the shed could still be susceptible to thunder charge. Will fusing be suitable on panels and battery?

If there is a lighting storm (rare where I live) and I'm around I will likely switch the whole system off anyway due to my own Paranoia!

Thanks

 

[DThames]

Hi,

Thank you. I'm not sure about LiFePo4 myself as I feel they are a little more unstable then lead and I don't really want to cause any fires if I can help it!?

What about the earthing situation, is that needed? Bare in mind my load is only about 15-20w, all low voltage 12v and I will not be using an inverter, however, I understand that a panel on a roof of the shed could still be susceptible to thunder charge. Will fusing be suitable on panels and battery?

If there is a lighting storm (rare where I live) and I'm around I will likely switch the whole system off anyway due to my own Paranoia!

Thanks

Lithium Ion have the chance of fire. Lithium Iron Phosphate don't have the same concerns. Lead acid works but not as well.

 

[killersheep34]

OK, so I'm in business.. Excuse the non coloured wiring, it is just speaker wire.

Load 3 is currently not finished but will allow for some leds to be dimmed.

My question is, I want to make some decorative led lights. Am I best using 12v leds (obviously with resistors in series) or using a step down transformer and wiring all my leds to a 3v output? Which is most efficient?

Thanks in advanced.

 

[45North]

Whatever's most convenient depending on the topology of your lights.
For me, for example, I'd be combining existing lights in series to add up to 12vdc strings. I have a pair of yard spots, 12v 5w nominal which really can run down to around 5v. So, I would just buy a few more LED's and add them to the mix.
If your controller has USB outputs you could run some lights off that as well but I don't imagine it's switched through the controller like the load terminals. Edit: I don't see any USB outs on your Renogy, but many others do.
It's a hobby, have fun with it!
Experiment, and then you'll know!

 

[DThames]

You can get LED lights on a spool, just cut and connect to 12v DC. They have current regulation built in. They are a little bit power hungry if you use a lot of them but they are very easy to connect and use.

 

[killersheep34]

Hi,

My project is coming along now, but I have a question.

I have some led string lights I want to add to my circuit, and i have measured the voltage of the AA battery pack output to be 2.91v.

What is the best way to connect these to my 12v battery?

I was thinking a 12v to 3v buck convertor but my concern is that my battery actually reads about 13.2v, so would this equate to over 3v and therefore shorten the life of my led's or worse, pop them?

I did think about one like this... ebay link where I can force it to 2.5v?

Also, how do I work out the current my set will draw. Do I just measure the resistance and work it out from there?

Thanks

 

[killersheep34]

I didn't really want to do it as it involves a bit of messing around, but I guess I could wire 5 or 6 in series at a time and connect them like this in parallel?

Will they get too hot if I do this?

Thanks

 

[12VoltInstalls]

4 3V led lights in series on ~12V will get no hotter than 1 3V light on ~3V

 

[killersheep34]

Perfect, thank you.