# 12 volt light bulb compared to 120 volt



## budgetprepp-n (Apr 7, 2013)

Hi 
I checked a 120 volt LED light bulb using a inverter it pulled 9.6 watts I thought that was pretty good.

Today my 12 volt LED came in the mail. it looks a lot like a standard LED bulb.
It's bright also just like a 120 volt bulb when I checked to see what the draw was
it was .3 amps that should be 3.6 watts .3amps x 12 volts= 3.6 watts < is that right? 
If I'm correct on figuring out the watts I'm impressed. I thought for sure it would be a lot higher.

I don't have a meter for measuring Lumens to see how bright it is compared to a 70 watt bulb
but I do have one ordered and I'll let you know

At $5.99 with free shipping this could be just what is needed in campers or BOL 

I'm thinking of charging up the 12 volt car battery and see how long this will run


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## HuntingHawk (Dec 16, 2012)

I=P/E which is watts divided by voltage.

3.6 divided by 12 would be 0.3amps.

9.6 divided by 120 = 0.08amps. But if running it off batteries & an inverter it would be 0.8amps draw off the batteries.


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## paraquack (Mar 1, 2013)

Were you looking at using 12 volt bulbs in your house and set up house to be on 12 volt during a SHTF event? While doing so would eliminate the cost of the inverter, 12 volt doesn't "push" it's way over long distances very well. Even though you would loose efficiency with an inverter, the 120 voltage would probably work better in the long run in the house. IMHO.


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## budgetprepp-n (Apr 7, 2013)

paraquack said:


> Were you looking at using 12 volt bulbs in your house and set up house to be on 12 volt during a SHTF event? While doing so would eliminate the cost of the inverter, 12 volt doesn't "push" it's way over long distances very well. Even though you would loose efficiency with an inverter, the 120 voltage would probably work better in the long run in the house. IMHO.


I agree


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## alterego (Jan 27, 2013)

How many lumens is each bulb.

When you are saying they look bright. the only way to measure is advertised lumens.


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## LunaticFringeInc (Nov 20, 2012)

> I'm thinking of charging up the 12 volt car battery and see how long this will run


\

Please do! I would be very interested in the results!!!


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## budgetprepp-n (Apr 7, 2013)

alterego said:


> How many lumens is each bulb.
> 
> When you are saying they look bright. the only way to measure is advertised lumens.


Both are 600 lumens


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## MrAnalogy (Sep 9, 2013)

paraquack said:


> Were you looking at using 12 volt bulbs in your house and set up house to be on 12 volt during a SHTF event? While doing so would eliminate the cost of the inverter, 12 volt doesn't "push" it's way over long distances very well. Even though you would loose efficiency with an inverter, the 120 voltage would probably work better in the long run in the house. IMHO.


The loss for 12v DC *is* 10x that of 120v AC bit it's fairly insignificant. I suppose you might run into a problem where a 1% voltage drop is a problem for some device.
Line loss is, I think, only an issue on really long runs.

For example, you can use the calculator below. For 1 AWG wire there is only a 1% loss at 500 feet with 12v DC, far less than the gain in efficiency.
(AC is used for transmission lines b/c they are much much longer).

Voltage Drop Calculator


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## dwight55 (Nov 9, 2012)

Just for example, . . . if you wanted to run a couple of lights from your main panel to your bedroom, . . . say 50 feet distance all together, . . . and like most houses, the wiring is 14 AWG copper, . . . you would have a 16% loss in voltage.

That should significantly drop the lumens, . . . but then again, . . . when the SHTF, . . . most of us will not be sitting in bed trying to read a novel or the encyclopedia. Lights will be more for getting around and getting done.

May God bless,
Dwight


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