Simple Lighting Setup

[nuts]

Hi Guys,

I have an 80watt panel mounted on the roof of a shipping container, I want to run the power to a battery (110amp) in the shed to run some led's off. Its around 20m/60ft(?) between the panel and battery. Whats the minimum gauge wire i can use. I have a roll of that 10 gauge twin speaker wire? Would this do? Could I run another panel/s thru same. I realise its light but then only very small current, would i be getting much through? Just want to get an idea before i run this light cable.

Thanks, Paul

[Mike90250]

80W panel @ 12V = 6.6A

10ga is safe for 30A, Speaker wire ought to handle 15V, but I'd put a 10A fuse, close to the charge controller, in case the insulation dies or gets cut, and a short develops in the PV's speaker wire.

Voltage Drop Calculator (spreadsheet format) can be found here: http://www.uwgb.edu/nevermab/voltage...alculator_.xls

Shows about a .8V (4.7%) drop, which is a significant amount. If you have enough wire, double it up, with 2 runs of 10Ga, and that should help, and get the drop below 3%, which is the max allowable (suggested)

[russ]

wire gage

Isn't wire one of the cheapest things in the entire installation?

I would tend to always error on the safe side and go bigger than deemed necessary - good insurance!

[nuts]

Thanks guys. I guess it is only a 'cheap' install, and I have the big roll of speaker wire already doing nothin' Perhaps I could get some 8ga, cheapest Ive found here (Australia) would be 2/300 for a similar size roll (or dearer by the m/y) Could be a plan. It may get bigger, just cant see it atm as I was just after lighting...

[nuts]

I've done some more reading. Thought i'd better err on the safe side and bought a roll of 4agw cable. I found the xl doc a bit difficult, thought overkill might account for being easily muddled

[nuts]

80W panel @ 12V = 6.6A

but I'd put a 10A fuse, close to the charge controller, in case the insulation dies or gets cut, and a short develops in the PV's speaker wire.

Just want to dble check and make sure i understand:

So I have run 4gauge +ve and -ve from the panel 60' to the shed. Can I put the charge controller in the shed (with the batteries) so i dont have to run more 60' wires? The fuse would go between battery and charge controller, closer to the controller than the battery (Ive wired a car amp before and the fuse went close to the battery)?



Thanks- Paul

[nuts]

Im also wondering: The huge 4 gauge leads, is it going to work to just solder the tiny charge controller leads into their ends? (sorry, the theory escapes me a bit on what's happening with the voltage if i do this)

[Mike90250]

Put a 10A fuse, in the PV wires, to the charge controller (I think you have 6.6A of PV) close to charge controller. If the controller fails, the 10A will help protect the wires to the PV's.
Also, put a 10A fuse, close to the battery, for the charge controller. It might be redundant, but you are wanting to know.
Also, close to the battery, in the inverter feed wire, use a properly sized fuse (inverter manual should call out wire and fuse size) to protect the inverter wire.

Charge controller should be fairly close to the battery, but the inverter should be the closest.

When you bolt the wires to the battery, the same bolt can connect the heavy inverter lead to the battery terminal, and also the charge controller lead. No need to solder them to anything.

[Sunking]

Isn't wire one of the cheapest things in the entire installation?

Not always, especially if you have to use wire that is $5/ft because the run is so long it has to be the size of your thumb to over come voltage drop.

[vendraline]

hey Paul,

Using less current to generate more light would be be possible by only LED, as it generates its own light without any external resources, the planning you mentioned could be possible with LED lights.



Mod note - links not allowed


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[jago888]

Hello dude..I really appreciate your work on the light setup which is very hard work i think 12 volt wire is the best wire for your setup..How much bulb is in your setup?