LED Power Consumption?

gary_roberston

Newly Enlightened
Joined
Jul 9, 2005
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5
Hello everyone! I am obviously a 'newbie', and I was sure hoping one of you could help me out, PLEASE???

I am a student working on a project for class. I need to utilize an LED light cluster to illuminate my project(I already have the cluster). I am trying to figure out power consumption. Can anyone help?

My LED cluster is 12v, and rated 180mA, 1.3 watt. I am trying to figure out how long they will run on the following gel cell batteries (assuming the battery is at 100% charge):

12v, 1.2 ah?
12v, 2.2 ah?
12v, 4.0 ah?

Thanks in advance for ANY help calculating this!

Sincerely,

Gary Robertson
[email protected]
 

Doug Owen

Flashlight Enthusiast
Joined
Jan 30, 2003
Messages
1,992
Howdy Gary,

In broad terms you can divide 1.2 Ah by .18 A and get an answer (in this case 6.6) in hours (the Amps parts cancel each other). The rub is the Ah rating of a battery is at a 20 hour rate, at faster rates, you get less capacity, in this case probably closer to 4 hours and a bit. The 4 Ah one, OTOH, will probably be quite close to the 22 hours this simple estimate will give.

Doug Owen
 

Doug Owen

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Jan 30, 2003
Messages
1,992
One other point, if you care about the battery, don't discharge it more than about half way. Even 'deep cycle' batteries loose a lot of life on even a few (severe) discharges. It can even prove fatal the first time. Under no conditions drain it below 11.0 Volts.

Doug Owen
 

VidPro

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Apr 7, 2004
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"My LED cluster is 12v, and rated 180mA, 1.3 watt."

i am really bad at math, but your watts rating doesnt seem to add up to me. i get 2x as many watts from the ma and volt specs
so i put it into my calculator, and it still isnt saying the right thing.
so you might check that.
 
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