Community Forums

trhendr · 04-16-2013, 11:38 AM

I have a Innsbruck 31 foot trailer. It has both house power and 12V systems onboard.

I know for example that most of the pancake lighting is 12V because it uses 921 Automotive style bulbs (well technically, it used to use... they've been replaced with 36 Warm White LED panels).

I want to add decorative LED strip lighting and attach it to the I-Beams underneath each side of the trailer (okay, it's cheesy, but it will be quite a light show!).

I'm wondering, if the LED strip lights pull about 4 Amps of power, should they be powered by a House power (120V) connection to a 12 Volt power supply for the lights, or could I simply tap into the 12V system already in the trailer? Is 4 Amps of power a lot with respect to what would normally be available in the trailer? (I'm using teh value of 4 Amps because I believe that is the maximum possible with this particular vendor's LED strip lights. I don't know that they actually use that amount.)

When connected to house power in the campground - I know there is an inverter which provides power to the 12V system. Is there any way to determine the specifications? I'm pretty sure the breaker box is a WFCO brand or whatever that popular brand's name is similar to that.

In summary, I guess I'm looking for recommendations as the best connection for the power source?

Thanks!

-Tom-

Go Dawgs · 04-16-2013, 11:44 AM

All your lights work off both systems. When plugged into power you are not working off the battery. I would hook them into a switch that would do the same.

beenthere · 04-16-2013, 12:01 PM

i think what he meant is can he just tap into a 12v wire// and if he does that he would have to know how much power that wire is already drawing for power...i always suggest that if you want to add a bunch of 12v power to install a 30amp relay and then to a fuse block that you have to addd the spade fused to and you add fuse for that requirment.. you can get fuse block in any arrangement like 4 to 10 fused power leads ....just attach different light or power needs to one of the fused blocks.....jeff

trhendr · 04-16-2013, 12:22 PM

Quote:

Originally Posted by beenthere

i think what he meant is can he just tap into a 12v wire// and if he does that he would have to know how much power that wire is already drawing for power...i always suggest that if you want to add a bunch of 12v power to install a 30amp relay and then to a fuse block that you have to addd the spade fused to and you add fuse for that requirment.. you can get fuse block in any arrangement like 4 to 10 fused power leads ....just attach different light or power needs to one of the fused blocks.....jeff

I could tap at an appropriate place.

What I'm trying to ask, is the following:

What's better? To take the power from the 12V system, or the 120V system?

I'm sure I could wire direct to the inverter if need be for 12V, no need to tap an existing wire.

If I run it off of 120V - I'll try to tap that power at the circuit box as well.

-Tom-

Qwert66 · 04-16-2013, 12:30 PM

Simple answer - depends...

Some led's while they work fine at 12vdc cannot tolerate 13.5-14vdc and will burn out prematurely. When your batteries are being charged they may reach the 14volt mark and if you are direct connected then could toast the led's.

Recommend you determine led acceptable dc voltage input range or at least add in a hi watt resistor if unknown to feed from batteries.

Regulated power supplies fed with 120vac have better controlled vdc outputs than running from a battery/charger combo.

The better choice is always to run a 12vdc device with 12vdc so as to not have the losses incurred to convert energy from 120vac to 12vdc. Theory prevails here but may not be practical in your case.

beenthere · 04-16-2013, 12:34 PM

another reason to use the relay and hooked up to convertor.. or buy the quality led's as they have wide voltage range...jeff

bluepill · 04-16-2013, 12:36 PM

If you have (or can access) an older tower style computer, you can salvage the power supply from it. It has very well regulated 12 and 5 volt power outputs.

beenthere · 04-16-2013, 12:45 PM

those are mostly only 3-5 amps....in computer power supply unless very high end...jeff

tompen · 04-16-2013, 01:07 PM

KIS (keep it simple) hook into the 12V system with a fuse and switch. 4 amps is not much. Two 4 amp strips fused with 10 amp fuse and switch and you are fine. Just make sure you don't pull your 12V from the load side on another circuit. I would go as close to the battery as possible. 14-16 gauge wire.
My 2c