# LED Worklight Questions, odd project



## 12guns (Aug 18, 2012)

I have searched for everything I know to search for and have not found a clear answer to a couple questions. Forgive me if this has already been covered, I could not find it. I also have an odd project that I would like some help with. 

I'm looking at LED worklights, most have 4-6 LED's and are around 1k lumens. How can I calculate runtimes? I'm working with a 12volt system and will either have a deep cycle battery or a small gel-cell, depending on runtimes and such. I guess I don't know enough about amphours and amp draw. Here's one I'm looking at: 
http://www.visionxusa.com/LED-Solst...LED_POD_20_DEGREE_NARROW_BE/product_info.html

It says 960 lumens, 083A amp draw. 10Watt. How long with that run off of a single 12V 7.2A gelcell? Silly question for many of you, so don't laugh!

My project:
I have two uses, one will be for a back up light on my Land Cruiser. Mainly for duck season backing boats and such. (Draw doesn't matter on that one.) Can I wire straight into a hot 12v and ground? Do I need some kind of regulator? 

Second and most important, will be for a flood light above my smoker! A friend and I built a smoker that is mounted on a 4x6 trailer. I have not figured out the design of the light yet, but I would like to have a tall pole with the light at the top. Then run wires down (away from any heat) and to a deep cycle battery. I would assume good runtime w/ such a large battery, but wanted to ask you guys first. With a 1k lumen flood LED, I should be able to cover my entire work area. Thanks for any help!


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## 12guns (Aug 18, 2012)

I found somewhat of an answer through more google searching. Somewhere I read that a single 24 watt LED pod can run 10 hours off of a 22 amp battery. I'm having trouble looking up amperage on a deep cycle battery, but I would guess them to be 50-60 amps? If that is the case, my little 7.2A gelcell is not enough to even mess with, but a deep cycle battery could run a high power 24 watt LED for some 20+ hours. That's what I'm looking for. Now on to the design for a semi portable tower. Let me know your thoughts and if I'm close on my math.


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## Trevtrain (Aug 19, 2012)

The very simplest math would suggest that if you divide the capacity of your battery (say 22 AmpHour) by the current drawn (0.83Amps) you will get the runtime. (in this case about 26 hours).

In reality, I doubt it would be quite that simple since you can't run the battery down completely, and we don't know at what current draw the 22AH rating is given for. Perhaps you should contact the company (visionxusa) directly and ask them for advice???


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## 12guns (Aug 19, 2012)

Thanks for the reply. "simple math" is an understatement! I realized how to answer my question after some more reading. My bad. I still didn't know if 083A meant .83 or 83 (although 83 would be ALOT of draw. So my little gelcell will run the 24 watt light for 8.67 hours if completely depleted, so 3-4 hours shouldn't be a problem. Forgive the dumb question, and thanks for the reply!


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## Trevtrain (Aug 19, 2012)

No problem - the only dumb questions are the ones we don't ask!

Yep, 083A on the site is pretty badly written, but the giveaway is the 10Watt rating. Volts x Amps = Watts so at 10Watts it has to be less than 1 Amp.

I wonder about regularly running your little gell cell down to half capacity though. Not sure if a sustained 1 Amp current would be a good thing. Also, gell cells have a more fussy charging regime than the typical auto battery. You might be better to have a second, larger deep-cycle auto type battery in the cruiser and use that, especially if your car alternator is how you planned to recharge it on trips away.

http://batteryuniversity.com/ is a great site for more info on this.


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