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Discussion Starter #1
I was wondering if someone could please me.

I am looking at a project where I would like to have 12 volt lights installed about 250 ft away from my garage. I was wondering if I could plug a transformer into my outside garage recepticle and run 16 AWG low voltage wire to a battery charger to charge a 12 volt battery which would then power the lights.

I'm having a tough time finding a battery charger that accepts low voltage AC input (do they even exist?).

A solar panel is not an option unfortunately due to too many trees.

Basically all I want to do is charge a 12 volt battery that is 250 ft away from my house without running 120 V wire (and not use solar as just mentioned).

Any ideas?

Thanks
 

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I'm curious why you'd want to run wires to charge a battery and then run lights off of the battery. Why not just run a low voltage line and run the lights directly off of it?

How big (in watts) and how many lights are you planning on installing?
 

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Discussion Starter #3
Good, question. Basically I just used lights as an example. I will run various 12 v electronics off it it a different times (lights, gate opener, inverter for radio, etc)
 

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Mmmmkay.... You aren't going to do what you describe with 16 gauge wire.

You could put your battery charger in your garage and connect the 12v output leads to an 8-2 low voltage cable and at 250 ft you you trickle charge your battery at no more than 5 amps. You'd have to figure out if that would be enough to keep the battery charged for whatever you intend to use it for.

Or you could just run the 120v line using 12-2 UF (direct burial) cable and you'd have a single 120v/15A outlet that you could then use to power 12v lighting, your gate opener, radio, etc...

250 ft of 8-2 low voltage cable or 250 ft of 12-2 UF are both going to cost you right about $200 each so that cost is kind of a wash between them.
 

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Discussion Starter #5
Thanks very much Jim!

The only reason I can't do 120v is that I am going through a ton of trees and there is no way I can get it buried to the required depth. I figured low voltage wire would be safer since I will be digging the trench all by hand and the depth won't be as deep as I would need with 120v.

I have been looking online and came across this https://www.powerstream.com/24vac-battery-backup.htm and this https://www.altronix.com/products/SMP3 would either of these work with 16 gauge 2c undergroud low energy circuit cable low voltage landscape lighting cable 30V FT-1 (is what is written on the cable)
 

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The problem is voltage drop at 250 feet.

I calculated a 120v circuit to get 15 amps at 250' with a 3% Vd would require a #4 Cu wire. A #6 would get you close with maybe a 5-7% Vd (I didn't do the math). Dropping it to 12 or 24 volts would certainly be safer, but voltage drop is still a factor in the size of wire needed to get the amps out there at that distance.

16 gauge copper wire @ 12v @ 250' will get you about 0.144 amps. Twice that at 24 volts.

What is your expected load in amps or watts?
 

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Discussion Starter #7
Thanks very much Jim!

The only reason I can't do 120v is that I am going through a ton of trees and there is no way I can get it buried to the required depth. I figured low voltage wire would be safer since I will be digging the trench all by hand and the depth won't be as deep as I would need with 120v.

I have been looking online and came across this https://www.powerstream.com/24vac-battery-backup.htm and this https://www.altronix.com/products/SMP3 would either of these work with 16 gauge 2c undergroud low energy circuit cable low voltage landscape lighting cable 30V FT-1 (is what is written on the cable)
Disregard the powerstream, I don't think its a battery charger.
 

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I have been looking online and came across this https://www.powerstream.com/24vac-battery-backup.htm and this https://www.altronix.com/products/SMP3 would either of these work with 16 gauge 2c undergroud low energy circuit cable low voltage landscape lighting cable 30V FT-1 (is what is written on the cable)
The first one isn't what you want at all. The 2nd would work to produce 12v DC but where are you going to get 24V AC to feed it? It'd be a whole lot easier (and cheaper!) to just use something like this: https://www.amazon.com/VETOMILE-Maintainer-Indicators-Automotive-Batteries/dp/B078NQWPJW/ref=pd_lpo_sbs_107_t_0?_encoding=UTF8&psc=1&refRID=HEFDGZBETRRNS3CAVPAC&dpID=51mJMbDyPUL&preST=_SY300_QL70_&dpSrc=detail

And 16 gauge is way to small not matter what. At 12VDC and 2.5 amps, the max length for 16 gauge wire is ~24 feet before you start dropping voltage. A 250' run of 16 gauge wire will drop your voltage to 9.5v and that isn't going to work to charge your battery. You'd need 8 gauge at a minimum (ideally 6 gauge or larger) to avoid voltage drop.
 

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Discussion Starter #9
The problem is voltage drop at 250 feet.

I calculated a 120v circuit to get 15 amps at 250' with a 3% Vd would require a #4 Cu wire. A #6 would get you close with maybe a 5-7% Vd (I didn't do the math). Dropping it to 12 or 24 volts would certainly be safer, but voltage drop is still a factor in the size of wire needed to get the amps out there at that distance.

16 gauge copper wire @ 12v @ 250' will get you about 0.144 amps. Twice that at 24 volts.

What is your expected load in amps or watts?
Honestly I have no idea. All I know is that a 12 volt deep cycle marine battery currently does everything I want it to do, I just would like a way to charge it in place instead of carrying it back and forth all the time. (Sorry, total noob). If the Altronix charger would work then I guess whatever its load is? My understanding is that using the Altronix I can supply it with 24VAC and it would trickle charge a 12Volt battery?
 

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The powerstream isn't a battery charger per-sae. It's a UPS for small, low volt equipment. The Altronix will require 4.6-4.8 amps minimum, so basically 5 amps.
 

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Discussion Starter #11
The first one isn't what you want at all. The 2nd would work to produce 12v DC but where are you going to get 24V AC to feed it? It'd be a whole lot easier (and cheaper!) to just use something like this: https://www.amazon.com/VETOMILE-Maintainer-Indicators-Automotive-Batteries/dp/B078NQWPJW/ref=pd_lpo_sbs_107_t_0?_encoding=UTF8&psc=1&refRID=HEFDGZBETRRNS3CAVPAC&dpID=51mJMbDyPUL&preST=_SY300_QL70_&dpSrc=detail

And 16 gauge is way to small not matter what. At 12VDC and 2.5 amps, the max length for 16 gauge wire is ~24 feet before you start dropping voltage. A 250' run of 16 gauge wire will drop your voltage to 9.5v and that isn't going to work to charge your battery. You'd need 8 gauge at a minimum (ideally 6 gauge or larger) to avoid voltage drop.
I currently have a 40VA class 2 transformer that is giving me 26.8 at the end of the 250 ft run of 16 gauge
 

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I currently have a 40VA class 2 transformer that is giving me 26.8 at the end of the 250 ft run of 16 gauge
It will show on a volt meter that you have that amount of voltage, until you put a load on it. That's when you truly get the voltage drop.
 

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Discussion Starter #13
It will show on a volt meter that you have that amount of voltage, until you put a load on it. That's when you truly get the voltage drop.
Ahh, I didn't know that. (See I'm learning, lol!) I really appreciate the help guys :bigthumb:

Could I use this https://www.powerstream.com/dc5g.htm and not worry about a battery at all? (assuming the voltage drop once I put on it isn't too severe?)
 

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The first one isn't what you want at all. The 2nd would work to produce 12v DC but where are you going to get 24V AC to feed it? It'd be a whole lot easier (and cheaper!) to just use something like this: https://www.amazon.com/VETOMILE-Maintainer-Indicators-Automotive-Batteries/dp/B078NQWPJW/ref=pd_lpo_sbs_107_t_0?_encoding=UTF8&psc=1&refRID=HEFDGZBETRRNS3CAVPAC&dpID=51mJMbDyPUL&preST=_SY300_QL70_&dpSrc=detail

And 16 gauge is way to small not matter what. At 12VDC and 2.5 amps, the max length for 16 gauge wire is ~24 feet before you start dropping voltage. A 250' run of 16 gauge wire will drop your voltage to 9.5v and that isn't going to work to charge your battery. You'd need 8 gauge at a minimum (ideally 6 gauge or larger) to avoid voltage drop.
So use the Vetomile and run 8/2 (preferably 6/2) to the battery?
 

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Honestly I have no idea. All I know is that a 12 volt deep cycle marine battery currently does everything I want it to do, I just would like a way to charge it in place instead of carrying it back and forth all the time. (Sorry, total noob). If the Altronix charger would work then I guess whatever its load is? My understanding is that using the Altronix I can supply it with 24VAC and it would trickle charge a 12Volt battery?
Quickly reading it's specs, it would charge a 12v battery, but is not designed to charge such a large battery. Those boards are more for small batteries like in a small alarm system or small fire alarm system. They're designed to charge a small battery fairly quickly, then trickle. Charging a large battery requires it to run "full throttle" for so long that they can't handle the prolonged heat for a long time, thus they die quickly. Some fire alarm systems I've installed have 2) 12v batteries (24 volt system) that are larger than motorcycle batteries, and their chargers are huge compared to that Altronix. Maybe 6-10 times larger.
 

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So use the Vetomile and run 8/2 (preferably 6/2) to the battery?
That will work as long as you aren't doing heavy duty stuff with the battery and leave it all connected all the time. If you draw down the battery it will take a while for it to fully recharge.

Technically, if you use 8-2 wire you'll still have some voltage drop with any run over 197 ft. But that charger puts out 13.8 volts DC and you'll still be above 12 volts at 250 ft. So it will work but isn't ideal.

A 6-2 cable won't have any noticeable voltage drop until you get to 267 ft.
 

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Trying to transmit 12V that far and do any useful work with it is a fools errand. Voltage drop is constant for a given current and work (in watts) is the product of voltage and current. Higher voltage == more work.

Take your 12-2 UF or whatever you decide to run and put a plug on the end that's near the AC source. It becomes an appliance then and is not covered by the NEC. Make sure you connect it to a GFCI protected outlet and you'll be covered safety-wise. That is a better half-assed solution than running 12V to charge a battery.

Or just do it right the first time. That way there are no regrets! Use a sub-soiler to cut the trench - this is a tractor forum!

EDIT: FWIW, 200 feet of 10AWG (that's 400' total) will have about 2 volts drop @ 5amps.

Al
 

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Technically, if you use 8-2 wire you'll still have some voltage drop with any run over 197 ft. But that charger puts out 13.8 volts DC and you'll still be above 12 volts at 250 ft. So it will work but isn't ideal.
A charger has to deliver more than 13.8 volts to charge a lead-acid battery. Specifically, the charging voltage has to be higher than the open circuit voltage of the battery for any current to flow. If the charging voltage drops below that, no current flows and thus no charge. How much voltage is needed at the battery to deliver a particular current is a relatively simple calculation, but you'd need to know the internal resistance of the battery to figure it out.

Al
 

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No disrespect intended Al....

Trying to transmit 12V that far and do any useful work with it is a fools errand. Voltage drop is constant for a given current and work (in watts) is the product of voltage and current. Higher voltage == more work.
No, work in watts is work in watts. A fixed load will have a fixed resistance, thus a higher voltage will reduce the amperage. Because a watt is a watt. P=E/I, or more truly, P=I(squared)R.

Take your 12-2 UF or whatever you decide to run and put a plug on the end that's near the AC source. It becomes an appliance then and is not covered by the NEC.
First, it does not become an appliance, unless you want to have an agency certify and list it as such. Even then, appliance installation is under the scope of the NEC. Second, neither UF cable nor any cord cap I know of is listed for use with the other, so it does fall under the scope of the NEC, as the NEC does state that equipment, etc. shall be used as per their listings. Have I seen it? Of course I've seen hillbilly extention cords. Doesn't make it right, nor safe.

Make sure you connect it to a GFCI protected outlet and you'll be covered safety-wise. That is a better half-assed solution than running 12V to charge a battery.
Or just do it right the first time. That way there are no regrets! Use a sub-soiler to cut the trench - this is a tractor forum!

Al
Now that I'll agree with :thumbup1gif:
 

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No disrespect intended Al....

No, work in watts is work in watts. A fixed load will have a fixed resistance, thus a higher voltage will reduce the amperage. Because a watt is a watt. P=E/I, or more truly, P=I(squared)R.
None taken.

The point I was making, not very well, is that 120V will allow for more work at the destination than 12V with the same current. The voltage loss and energy loss (in watts) is identical given the same transmission line. Much the same as why electric power is transmitted at hundreds of thousands of volts over long distances.

I haven't looked at the NEC in many moons, but the it used to clearly state that the code ended at the outlet. Anything beyond that was an appliance and UL/CE took over from there and those are entirely voluntary. If it has changed, discount what I wrote.

Just do it right and be done with it.

Al
 
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