Author Topic: 9 LED Flashlight  (Read 2478 times)

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9 LED Flashlight
« on: November 16, 2009, 10:40:37 am »
I didn't think the $3.99 Flashlight that I had picked up from Office Depo would have been so great. I've been wanting one for over a year now and I could only find them for 20 bucks a pop. This one caught my eye and i bought it. Prior to purchasing this one, I also Purchased a 7th Mag Lite. I lost all the other mag lites and the one I had contained a shot bulb. I purchased the new maglite because it had a bulb in the lite, and it had 2 spare bulbs. So now i have 2 maglites with 1 spare bulb.


The 9 Led flashlite puts the maglite to mortal shame. I thought the maglite was bright but after comparing it with the led lite I wasn't far from chunking Bricks at the maglite. I can honestly say I regret buying the maglite after purchasing this led light.



Meanwhile, How long will this Led lite last? Correct me if I am wrong but I am only assuming that the leds draw 20 MA per led. Thats .18 or, 180 Millamps. The led lite caries 3 AAA batterys, Which I have estimated to be 1000 millamps. Or 1k miliamp hours.

Since the current draw is 180 milliamp hours for these leds in parallel, and the 3 batteries are in series then we come up with 1 amp hour for this battery arrangement. Or, 4.5 watts since 4.5 volts * 1k Ma is 4.5 watts. So now we have 1 amp hour or, 4.5 watt hours. The leds are 180 milliamp hours or, .81 watt hours.

4.5 watt hours divided into .81 watt hours gives you 5.5 hours of continusly operation. WOW, I can leave this sucker on for 5 and a half hours!

But, My question is.....

WHY can you not purchase these lights that can hold 3 AA batterys instead of AAA batterys. "BOTH" are 1.5 volts.

AAA 1000 MAH
AA   2500 MAH

Hrm, lets do the math. 2.5/.81 13.8 Hours of Light. Hrm.
2.5 Amps * 4.5 volts is 11.25 watts.
We know the leds draw atleast 20 ma per led, "I assume" so;

.18 for total current * 4.5 volts ,,, Hey, this means we're using .81 watt hours to run these flashlights!

11.25 watts, "(AA)" series Divided into .81 Watt hours, "what the device consumes," leaves us with 13.8 Hours of Light Operation,,, WOW.

Or, 2.5 amps / .18 ma (180 MA) leaves you with also 13.8 hours of operation.. So, Basically it doesn't matter if you calculate in watt hours or amp hours, you still get the same result..

13.8 Hours, WOW, no wonder they don't want them to hold AA batterys. They'd Last Forever.

Ever try to find an MAH rating on a none rechargeable Battery... Right near to impossible... I ride with Duracell!

What batteries is your battery of choice? My current Digital multimeter last longer with Duracell, So i've chosen it for all my applications. Any proof to make me consider another brand?

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Re: 9 LED Flashlight
« Reply #1 on: November 16, 2009, 14:42:20 pm »
9 LED spotlight independently tested to run 20 days from a 6V sealed lead acid battery!



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Re: 9 LED Flashlight
« Reply #2 on: November 16, 2009, 22:26:06 pm »
1 watt is equal to 3.412 Btu's.

The Btu is the amount of Heat needed to raise one (Pound) not gallon, of water 1 degree Fahrenheit. So to raise one pound of water 1 degree, you'd need 8.3 btus to do so. One gallon of water is 8.33 Lbs.

Here is the formula, But first figure your Temperature difference. For example, If the gallon of water on the table was 70 degrees  and you wanted to raise the temp to 71 degree's then this would give you a TD of 1 degree. 70 - 71 = 1.

The Formula.

Pounds X 1Btu for water X Temperature Difference.

8.33 X 1 X 1 = 8.3 Btu's The amount needed to Raise the temp of 1 gallon of water 1 degree.

Suppose we had 3 gallons of water, Which weighs 25 Pounds. The water is at 70 Degree's, We want to raise it to 73 Degree's, A 3 degree Temp Difference.

25 X 1 X 3 = 75 Btu's would be needed to raise 3 Gallons of water 3 degree's.


Lets look at these Leds.

The Facts are, 1 Watt is Equal to 3.412 Btu's, So a 100 watt light bulb would be putting out  341.2 Btu's. 3.4 * 100

Our leds are .20 Ma per lite at 4.5 volts (.09 watts). 3.4 * .09 = .306 Btu's Per Led.
For 9 Leds wich draws .180 MA at 4.5 volts (0.81 watts)          3.4 * 0.81  = about 2.7 Btu's.

Lets say we have 18 leds wich draws .20 ma each at 4.5 volts. 360 ma total. 4.5*.360 = 1.62 watts

1.62 watts * 3.4 btu =  5.508 Btu's.   18 leds puts out about 5.508 Btu's of heat!

Have I gone Completely Insane?

Does anyone care to Correct any of this, Or state i'm completely insane. Please do.

Ok, To Clear this Up, 18 Leds Puts out 5.508 Btu's.
8.33 Btu's is needed to Raise 1 Gallon of water up 1 degree.

SO, we would need a bit more than 18 leds. And another question,, What happens when you do raise it up a degree... ? Does it start over and contunue to go up? Hrm...

Based on my very last question,,, If you read it to yourself,, It does not make since. It's like something is left out, Or not completely understood. Is anyone here smart enough to figure out what is missing, If something is missing? Based on the last question. It sounds to good to be true.
« Last Edit: November 16, 2009, 22:52:34 pm by Warp »

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Re: 9 LED Flashlight
« Reply #3 on: November 16, 2009, 22:35:30 pm »
coo coo....   lol.. i was reading some things on hydroponics the other day... they have been coming out with new lighting systems for the past couple of years.. they now also use led for growing plants... interesting thing is that the blue leds and and red are the best for plant growth..
they are using 1.05 watt leds. and one with around 280 is like 300 watts power consumption...
standard lights of today for indoors is a high pressure sodium or a metal halide. bulb system

a 300 watt 288 led light will put out to the equivalence of a 1000 watt high preassure sodium light system.. from what im reading

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Re: 9 LED Flashlight
« Reply #4 on: November 16, 2009, 23:01:14 pm »
Suppose the Gallon of water was already at 70 degree's.

8.33 * 70 = 583 Btu's.

Would this mean,,,, You would have to Add 8.33 Btu's to the already existing 583 Btu's in order to raise the temp to 1 degree higher? This makes More since "To Me." Does anyone understand what i'm saying here?

I think the Books does not cover everything. Perhaps the water is already Holding 583 Btu's before the needed 8.33 Btu is applied in order to raise the temp by 1 degree.

Meaning, you would have to use 591 Btu's to raise the 70 degree water gallon  by 1 degree.

(Now that makes allot more since to me.) Could this be the case? I'm comfident it is.

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Re: 9 LED Flashlight BTU's
« Reply #5 on: November 17, 2009, 06:58:21 am »
Ok The Following

A BTU is defined as amount of heat required to raise the temperature of one pound of liquid water by one degree from 60 to 61 degrees Fahrenheit at a constant pressure of one atmosphere. As is the case with the calorie, several different definitions of the BTU exist, which are based on different water temperatures and therefore vary by up to 0.5%: A BTU can be approximated as the heat burned in a single wooden match[1] or as the amount of energy it would take to lift a one-pound weight to a height of 778 feet.[2]

FOUND HERE http://en.wikipedia.org/wiki/British_thermal_unit


from 60 to 61 degrees Fahrenheit at a constant pressure of one atmosphere; That is what was left out.

That is why I was getting the negative Vibes in my conscious.

However, To fully compute what the facts are here is still a bit fuzzy to me (i'm lost). Anyways, there is more to heating water than what the research digs up, Based on this very post.

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Re: 9 LED Flashlight
« Reply #6 on: November 18, 2009, 00:46:29 am »
Ok, If the Water was already at 60 degree Fahrenheit then this would also mean the heat source "Not Connected" Would TOO be at 60 degree Fahrenheit!

Meaning, 1 BTU would heat the water Only starting at X degree's, Depending on the surrounding Temperature. In This case, I can see Leds heating water by 1 degree.

A Heat Source of 1 BTU would always make the water temp 1 degree higher No matter the surrounding Temp. For Example, If on a Particular day the water was at 35 Degree's, Then it would heat the water to 36 Degree's. If it was 90 Degree's that day, and the gallon of water was also at 90 degree's, The 1 BTU heat source would Raise it to 91 Degree's. Understood that to keep the water at a Fixed Degree Fahrenheit over a long period time would mean adjusting how many Btus would need to be applied.

For Example; It is 35 Degree's in the shop. It will take 291.5 Btu's to Raise this gallon of water to a temp of 70 degree's Fahrenheit.

Understood. It is now 68 Degree's in the Shop where Same Gallon of water is located. It would take 16.6 Btu's to keep the water Temp at 70 Degree's Fahrenheit (That Day.) As you can see the amount of Btu's Required to Maintain the water Temp depends on the Ambient Temperature!


Yikes.

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Re: 9 LED Flashlight
« Reply #7 on: November 18, 2009, 01:02:13 am »
  Could you Imagine what the result would be if you applied 10,000 Btu's to one gallon of water, Or even 1 Pound of water, Amazing...  :D