Electrical system option


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    Been thinking about how to reduce the power consumption by running everything on 5v except the 12v vent fan . There are just as many LED devices available as 5v  with no loss of light. The 5v LEDs are just as bright as the 12v ones. Think of the small LED flashlights that use 3 AAA batteries which is 4.5 volts – 3.75 if you use rechargeable batteries. Still run everything from a 12v deep cycle battery with a 5v step down unit. The link below will show what I am referring to. This is a small 12-24v step down unit that supports 25 amps @ a 5v. Seems like this arrangement would use less current than the 12v LED devices.

    What is your opinion ?





    It’s the total wattage that matters, not the voltage. If a device runs on half the voltage but draws twice the current you haven’t gained anything.


    It’s an interesting thought for sure, but I agree, 12V or 5V it really doesn’t matter. When thinking about battery life what matters is total current draw. Which you can determined from the wattage/power consumption of each device. Ohm’s Law can help to work that one out.

    Here’s a good write up on Voltage.

    I’m not sure, but you might want to also take into consideration the power consumption by the step-down.  Perhaps it is a negligible value but when dealing with low current devices such as LED’s I’m curious if there would be any net savings.


    I agree with rovineye and abrightwell.  it’s all about the watts, not the voltage.  plus, anytime you do a conversion (from 12v to 5 v, from 12v dc to 120v ac etc) there is an inherent loss of energy.  stick to 12v led lights etc and you’ll be fine.

    if you plan on taking a TV along, there are some smallish LED tv’s (21-23″) that are 12v and come with 120v to 12v power supplies, like you use with your laptop.  go to your favorite big box store and look at the backs of the small tv’s. I’ve checked recently and Samsung and LG tv’s are mostly 19v, but some of the off-brand small tv’s re 12v. I have a couple of 23″ LED tvs and they are rated at only 22 watts.  you can then build a cord with a cigarette lighter plug on one end and the right size power jack on the other end.  that would eliminate the inherent loss when using an inverter to convert battery power to 120v AC.  of course, if you’re camping where you have shore power, not an issue.


    I agree with the statements made about it’s all about the current (amps) requirements of a given device. But when you think about a flashlight that runs on 4.5 volts from a 650 milli-amp battery and lasts more than a week of steady use, I would expect those type of LED  would have a much lower current draw. But I have never seen specs that list a given LED current draw, have you?

    I come from a background of back-country Canoe camping in British Columbia and there is no TV or Radio or Phone service. I have no use for such things when camping. I am just tired of sleeping on the ground in a tent and age is starting to dictate what I am able to do .

    Bob D.

    Pretty typical an LED runs around 20-40mA at about 1.2-1.7 volts.  That’s one LED.

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