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Small Cabin Forum / Off-Grid Living / Off-Grid Solar Panel Setup for lights, electric fence, etc...
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StevenCumming
Member
# Posted: 16 Feb 2013 11:15
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Hello, I have put together a diagram of the setup I intend to have for a hut / cabin. It will be on a farm, and an electric fence energizer will be included. Just wanted to know anyone's opinion of this setup and any criticisms, or recommendations anyone has.

Thanks!
Electrical_Diagram.p.png
Electrical_Diagram.p.png


razmichael
Member
# Posted: 17 Feb 2013 13:12
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Hi Steven,

I'll take a short stab at some points but without more details on wiring distance, use etc it is really hard understand how you plan to use the system. Take this all with a grain of salt and these are only things to consider as I don't think there is anything wrong with the concept.
The battery looks like a sealed lead acid so this may not be the optimum choice for a cabin as it is harder to maintain. This battery is being sold for a vehicle where sealed is more useful. I do not know if it is a true Deep cycle or a hybrid. Given the limited demands you have it should be fine but this is a guess and it may be wise to consider something more robust if you truly think you will want to expand the system in the near future (perhaps a couple of deep cycle 6 volts).

With the lights, one thing to consider is going with 12 LED bulbs with more standard 120V bases (e27 etc). These are now easily available (I bought a 10 pack last year at about the same price - and selections on watts and colour). You selection are specifically down lights - less flexible, The nice thing about standard base bulbs is you have lots more fixtures to select at a much cheaper price.

Don't forget to consider voltage drop if you plan to wire these any distance from the power. You may need to consider wire gauge to keep the standard maximum 3% drop. Some debate on using standard 120 volt light switches with DC but given the really low draw this would work fine if you wanted to mount the more conventional switches - I used standard 20 amp 120V toggle switches form the local store. Given each is only handling maximum 2 LED lights this works fine.

Just some thoughts...

toyota_mdt_tech
Member
# Posted: 18 Feb 2013 09:01
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Steve, they already make a fully solar powered electric fence set up. It needs nothing, all self contained. I think its a capacitor discharge type system. Charges up on solar, battery to keep it working into the evenings etc. That will free up your cabin system.

StevenCumming
Member
# Posted: 18 Feb 2013 15:04
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Yeah but only difference is that the panels are usually 5-10 watts, and they charge around the same price for an eBay 120w here in Australia at our local farming stores. I would rather have it all in the same system so I can just draw from the panel for the fence for lighting and such at the hut.

Dillio187
Member
# Posted: 18 Feb 2013 18:21
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my take on it...you don't have enough panel for any kind of longer term use.. You only want to take your battery down to 50% at the absolute lowest (75% is even better). An 8-10% charge rate is recommended to keep batteries happy (so that's 10 amps for a 100ah battery). You ideally want your batteries to recharge the next day.

Do you know what the fence system draws over a 24 hour period? Determining your loads first and then working backwards is what allows you to design and build a good system, and keep in mind that your loads almost always will grow over time as things are added.

creeky
Member
# Posted: 19 Feb 2013 15:41
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electric fences are very low draw. so 120 watts of power to 100 amps of battery is pretty good. (pretty close to 10 amps at 12v?)

should handle your lights too.

and an mppt charge controller for 35 bucks. sheesh. that's cheap.
so, even if the system ends up under sized as you grow your needs ... you can always move it to an outbuilding for the fence/lights.

looks good to me.

Moving Pictures
Member
# Posted: 19 Feb 2013 20:27
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Quoting: creeky
and an mppt charge controller for 35 bucks. sheesh. that's cheap.


It is highly unlikely - nay, certain - that anything selling for $35 is an MPPT controller.

SE Ohio
Member
# Posted: 19 Feb 2013 20:54
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Have you looked at 12 volt 15 watt CF bulbs, comparing lumens vs the LED's? I like the CF lumens better than the LED lumens if that makes any sense- LED's tend to be a bit directional where fluorescent light is a bit more even. 12volt CF's pretty cheap here stateside compared to same lumen LED's.

Dillio187
Member
# Posted: 20 Feb 2013 09:49
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Quoting: Moving Pictures
and an mppt charge controller for 35 bucks. sheesh. that's cheap.


It is highly unlikely - nay, certain - that anything selling for $35 is an MPPT controller.


agreed 100%.

Also, my note about the undersized panels is not that I don't think the panels will recharge the battery (eventually) it's that batteries need a certain amount of amperage to keep them happy. In this case, it's to achieve a proper charge rate to allow the battery to bubble a bit and clean the lead sulfate off it's plates. Chronically under-charging a FLA battery in this manner is a sure fire way to send it to an early death.

StevenCumming
Member
# Posted: 20 Feb 2013 10:40
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Electric fences use very little power, as they only use the majority of their power when they are actually 'zapping' something for lack of a better word. Lights, and everything else will only be used on weekends, and even then, not very often. The solar panel and battery are very much overkill for the fence alone, because most pre-made electric fences have 5 or 10 watt panels, and a 7amp hour battery. Thank you all for your opinions.

volleypc
Member
# Posted: 20 Feb 2013 10:48 - Edited by: volleypc
Reply 


A couple of things.. first hte solar panels. Just to pass this on to you, you can buy two 145 Watt DM Solar Panels on Amazon for 320 (Free shipping if you are a prime member). Second, you need a fuse and disconnect between the panel and the charge controller. Second, the charge controller isnt really a MPPT charge controller. The way I know this is because I bought this same charge controller thinking it was MPPT about a year ago. You also need a fuse and disconnect between the charge controller and battery.

Between the solar panels and charge controller I used the mini anl fuses. The disconnects I used were the blue sea battery switches. You can find both on Amazon.

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