Voltage drop over 50 metres

[bumpy]

I would like to run a 12volt supply to LED lights in my drive. The run is 50 metres, the current will be say 10 amps and the wire is standard 1.5mm mains cable. Can anyone tell me what the voltage drop will be?

Have used Google, but calculators give results that are all over the place :(

[JohnJo]

29mV/A/m for 2-core 1.5mm2 70C pvc insulated cable carrying DC.

= 0.029x10x50

=14.5 volts

You’ll have -2.5 volts at the end, simples :)

120 watt is quite a bit of light using LEDs.

You’ll need to stick to mains voltage I think.

[bumpy]

Thanks
Point taken about the watts required for LED. It was just a guess :)

So assume 2 lamps at 10 watts each (12v) = 20 watts

I make the calculation 0.029x1.7x50
= 2.5volts??
What does this mean?

[JohnJo]

It means you’ll have reduced voltage in the circuit due to the resistance of the cable creating waste heat. If the lights have a wide operating voltage range, say 6 -13V you’ll be fine. If they need 12V exactly (unlikely) and you are only supplying 10V the lights won’t work.
Using 12V on an outdoor installation with a number of cable breaks/connection points may be troublesome. Get some corrosion and it’s lights out.
Why not use mains voltage with a 30mA RCD for shock protection?

[bumpy]

Thanks for the explanation. Look like mains voltage is the way to go :)