12V Switches When and Why

[Strop]

Ok, I am having a bit of confusion based on my limited understanding of electrical concepts and what I am see in some of the many photos I have looked at of these little creations we seem to have a fascination with.

I assume that all users of 12V systems should have a master switch that turns everything on/off. I am also assuming that for ease of installation it should be near the battery.

Next, as a result of discussion in another post, I think that charging stations using USB should be switched as they will still draw some current when not being used. It is in their design. The old traditional 12V cigarette lighter style charger only draws power when being used so it should not need to be switched.

Internal lights can be purchased with inbuilt switches - so you would think no need for any further switches.

So why when I look at photos do I see switched lights with what appear to be external switches. Charging stations (Non-USB) using switches. And why do I see fantastic fans with power switches next to them.

Am I missing something or are these people just being very careful in what they are doing or future proofing their builds in case they want to put unstitched alternatives in.

[noseoil]

The USB charging modules I'm using have the blue LED lights installed and will stay on all the time when powered. They are very bright & add more light for sleeping than I really want or need at night. I've added a switch for each one, to keep the battery drain to a minimum and get rid of the annoying light I don't want or need, but it is handy to see the light and know a car battery can charge the cell phone.



The "porch lights" I'm using don't have external switches on them, they're inside on the wall next to the doors, one per side (when the build is eventually finished). I wanted to have a sealed fixture & be able to turn them on and off from inside at night. I guess it just boils down to personal preference.

The reading lamps I chose have a switch on the base, because it's just easier to turn it on & off at the headboard while in bed and reading.

Since there's no right or wrong answer to all this, it comes down to your vision of a "complete" camping unit. What would you rather have if you could have anything you wanted? That's what I'm building for myself & my wife. I'm too old to sleep on the ground now & figure "roughing it" is best left to people my son's age and mind-set.



I just want to be comfortable, go out on the road whenever I want to and enjoy having a place to eat & sleep without paying for a room. If, along the way, I get a little carried away with the amenities, so what? Life is too short to not enjoy the time we have left to see things, take pictures & meet people!

[Dale M.]

Personally I like it dark when sleeping... We seem to be of a mind set that all (newer) devices has to have a LED on them to let us know there is power to device.... Which is sort of dumb, we are living on a world that is becoming more "energy conscious" and yet we tolerate theses little energy thieves into our lives because somebody (engineers-led manufacturers) think we need them....

Got to agree with "noseoil" on his comments on why we need switches.... We need to stop these little thieves from taking the finite amount of battery power we have between battery charging.... If taken on the concept of one single device its not much power but if you have 4-5-6 or more the cumulative amount is a good bit of energy...

Just for giggles walk around your home and count how many devices have glowing LEDS (check your TV, VCR, DSL Modem, any cell phone chargers) everything that has a remote control to turn unit on/off consumes a little energy full time to keep "switch" capabilities powered, we take these for granted because there is a "infinite" amount of power coming in to your homes supplied by a utility company...

Its more about conservation (and dark) and convenience than a fascination with switches....

Dale

[bc toys]

while we are on this does anyone have a D/C nite lite we have a grand baby that will be going with us soon and I'm thinking she or granny will want a lite in trailer I'm thinking about just wiring a single LED bulb to the fuse block

[Strop]

I understand to get rid of those little energy users.

Do fantastic fans have a master on/off switch or are they always on?

noseoil, to me a switch is a switch is a switch. The double switching just makes me think I have missed something, though it could be a replacement light that did not originally have it's own switch. With the roof fans it may be they are the fancy ones with rain sensors and thermostats.

Laurie

[MtnDon]

Do fantastic fans have a master on/off switch or are they always on?

Laurie

All models of fantastic fans have an on off switch. Some have extras, like reversing switches, thermostats, rain sensors, etc. But they all have an on - off and a 3 speed selector. http://www.fantasticvent.com/fan-tastic ... #model1200

[MtnDon]

As for the LED's that indicate the circuit is alive and ready those do not really consume much power at all. Our CTC has an LED voltmeter and a varibale speed PWM fan controller. I did wire them both with an on=off rocker switch. In part to kill the LED lights at night; in part because of phantom load paranoia.

The trailer was used for a trip at the beginning of October. When we returned the batteries (2 GC-2's) were fully charged with an at rest voltage of 12.77 volts. The trailer is in the side yard and is NOT connected to house power nor to any other input power. I left both the voltmeter display active as well as leaving the PWM speed control active. To be clear, the speed control switch that controls the electric fan was turned to off, but the 'ready' LED was on and the solid state electronics ready to go. Today the voltmeter read 12.71 volts, a reduction of 0.06 volts. Most of that drop is likely due to the self discharge that any FLA (flooded lead acid) battery undergoes.

It would seem to me, that unless the visible light output of the LED is bothersome extra switches are just that; extra and not really needed.

When parked and not in use a master disconnect at the battery positive terminal is all one needs.

Just my point of view.

[S. Heisley]

I used external switches on my porch lights so that I wouldn't have to open the door to turn on the light when I heard a noise outside (...bear or skunk?) or if some unknown person knocked on my door. Other than that and a battery disconnect, those are the only external switches I used. For USB ports, I bought a 2-USB unit that pugs into the 12V outlet plus gives me two additional 12V outlets...easy; but, I've never used it in the 3 years that I've camped with my trailer...haven't needed it.