12v tv type of wire

[sunnyday]

Hello all,
i recently bought a tv with 12v dc in on it at the back. i tried connecting them to my 12v batteries, being charged by a 120w panel. and just under a minute, wires would go really hot and soft.

tv is 12v @3.5amps.. what type of wire should i be using with distance of battery to tv like 20 meters.


Thank you,
Charles

[inetdog]

Hello all,
i recently bought a tv with 12v dc in on it at the back. i tried connecting them to my 12v batteries, being charged by a 120w panel. and just under a minute, wires would go really hot and soft.

tv is 12v @3.5amps.. what type of wire should i be using with distance of battery to tv like 20 meters.


Thank you,
Charles

Well, Charles, there are two different requirements in play here.
1. To carry 3.5A without heating and damage to the wires, you should have 22 gauge wire or larger. Typical "lamp cord" will be a minimum of 18ga. and that will give it enough mechanical strength. But speaker wire, especially cheap speaker wire can be 22ga or smaller. If you have a bad connection at the end of the wire, it will get even hotter.
2. To carry that DC for 20 meters without dropping so much voltage that the TV has problems (especially given that the battery voltage of 12 volts or less may actually be less than the TV is designed for!) may require a larger wire size. To get a voltage drop of 4%, for example, you would need to use 12ga copper wire, which is much larger.

Here is one online calculator which will help you plug in other numbers: http://www.southwire.com/support/vol...calculator.htm