# 100 Watt LED Chip & 18650 LiPo pack



## sportcoupe (Oct 28, 2016)

New member here. Long time experimenter.

The 100 watt LED chips are attractive for tinkering. Suppose I get a chip and want to power it with a 250w DC-DC CC Boost Step-up power supply using 18650 LiPo battery pack. I read I need ~32vdc at 3a to run these chips. The DC-DC Boost accepts 8-48vdc input and outputs 12-50vdc at 0.2-8A. Theoretically, I could use a simple 3S 18650 pack or a 3S2P to increase mah. Alternately, I could run a 6S2P 18650 pack. Seems the less batteries in series the better but the boost converter will run hotter. What are most people doing to properly power these 100 watt LED chips?


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## Lexel (Oct 28, 2016)

Usually people use battery pack of 22.2V
that 250W converter will melt with 3 batteries due to a way to high input current

watch this DIY vodeo for 100W flashlight

https://m.youtube.com/watch?v=jaJQ2fo4poU


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## sportcoupe (Oct 29, 2016)

Thanks for the reply.

I figured 3 series (3S) would have high current on input. I'll look at making at least 6S pack to run 22v input.

Is there another form factor LiPo cell that has at least the energy density of a 18650 and is less expensive?


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## Lexel (Oct 30, 2016)

You can buy here in forum 3400mAh cell for 3$ no way you get a lipo pack that cheap

and the 18650 cells are less sensible for low temperature 
and a lot more robust (mechanical)


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## ssanasisredna (Oct 30, 2016)

You are better off with a more efficient LED and less power.


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## sportcoupe (Oct 30, 2016)

Less power? No one wants less power, we all want more power.


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## degarb (Nov 2, 2016)

sportcoupe said:


> Less power? No one wants less power, we all want more power.


We want more power out. Less in. 

The claim is 100 lpw. .or 90. . Epistar, I believe. I feel my ac lights are less than 65lpw cool. . One 50 burned out by me leaving it on all day. Replaced it with a warm 45lpw. Cree has some true 400mh killers, but will be a while before overtaking a 600mh.

Oth, my Cree xpl run via buck, gets 373 lumens at 2watts. The next gen xpl2 should get 400 lumens. 

Always look at the graph dropped as power increases. 

On side note, the 1amp binning by Cree is counter productive to their sales, since you get 202 lpw one watt, 187 2w,161 3 watt, 100 guessing here at 10w. So, bin high sell low.


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## Enderman (Nov 4, 2016)

Usually people use non-18650 battery packs to power those LEDs.
3s or 6s RC lipo packs can supply dozens or hundreds of amps continuous, and you can get them in much higher capacities than 18650s.
I'm using multiple 6000mAh 3s 65C LiPOs for my upcoming flashlight project, with an LED that draws about 90W.


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## sportcoupe (Nov 5, 2016)

degarb said:


> We want more power out. Less in.
> 
> The claim is 100 lpw. .or 90. . Epistar, I believe. I feel my ac lights are less than 65lpw cool. . One 50 burned out by me leaving it on all day. Replaced it with a warm 45lpw. Cree has some true 400mh killers, but will be a while before overtaking a 600mh.
> 
> ...



Yes I am aware that there are higher efficiency LED's with huge lpw numbers, but they are not in high LED count chips. These 100 watt chips make it very convenient to have a lot of LED's in a small package.


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## sportcoupe (Nov 5, 2016)

Enderman said:


> Usually people use non-18650 battery packs to power those LEDs.
> 3s or 6s RC lipo packs can supply dozens or hundreds of amps continuous, and you can get them in much higher capacities than 18650s.
> I'm using multiple 6000mAh 3s 65C LiPOs for my upcoming flashlight project, with an LED that draws about 90W.



I agree a RC lipo pack is best option. It is also the most expensive when you need a 6s pack. I can do a simple 6s with 18650's cheap. There are no cheap lipo 6s packs I can find. If you know a source, I am listening...


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## Enderman (Nov 5, 2016)

sportcoupe said:


> I agree a RC lipo pack is best option. It is also the most expensive when you need a 6s pack. I can do a simple 6s with 18650's cheap. There are no cheap lipo 6s packs I can find. If you know a source, I am listening...


 
Hobby king has cheap ones? Not sure how cheap you're willing to go, I usually spend $50-100 on my 3s lipos because I want high output and many charge cycles.
If you're gonna use 18650s then yeah you cna put 6 in series but you should also put some in parallel if you are drawing several amps.
Like maybe if you will draw 4 amps, do 2 sets of 6 in parallel so that only 2A gets drawn from each?


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## Lexel (Nov 6, 2016)

Enderman said:


> Hobby king has cheap ones? Not sure how cheap you're willing to go, I usually spend $50-100 on my 3s lipos because I want high output and many charge cycles.
> If you're gonna use 18650s then yeah you cna put 6 in series but you should also put some in parallel if you are drawing several amps.
> Like maybe if you will draw 4 amps, do 2 sets of 6 in parallel so that only 2A gets drawn from each?



Even good low drain 18650 Lithium batteries like Panasonic 18650B can provide 5A without any problems

18650 Cells like 18650MJ1 can deliver 8A at 3500mAh

Samsung 18650-30Q can easily provide 20A at 3000mAh
The Samsung cells cost about 4$, so a 6S2P 30Q pack can deliver 40A, with [email protected] for 48$ A lipo pack costs at least 3 times more 
the only positive for Lipo packs is the weight and size
In durability and some other things the 18650 are way better


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## ssanasisredna (Nov 6, 2016)

sportcoupe said:


> Yes I am aware that there are higher efficiency LED's with huge lpw numbers, but they are not in high LED count chips. These 100 watt chips make it very convenient to have a lot of LED's in a small package.



They are, and in much less space so they focus better. That these are "rated" at 100W is questionable. They could put pretty much anything on them. 

That they are rated for 100W and only puts out say as much light as a good 60 or 70W should tell you something.

These are good for 200W: http://www.bridgelux.com/sites/defa...3 Vero 29 Array Data Sheet Rev E 20160829.pdf


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## Enderman (Nov 6, 2016)

Lexel said:


> Even good low drain 18650 Lithium batteries like Panasonic 18650B can provide 5A without any problems
> 
> 18650 Cells like 18650MJ1 can deliver 8A at 3500mAh
> 
> ...


 
Yeah but the more current you draw from a lipo cell the less runtime you get, and it also heats up more and gets reduced lifespan.
Drawing 10A from a lipo that is rated for 500A is much better than drawing 10A from a 18650 cell rated for 20.


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## AndyPost (Feb 18, 2017)

Noob question. I was going to link 3-3s batteries in Series to power 10 of these 100w LEDs. It seems like I'd have to have something to limit the amps to keep the LEDs from frying. If that's true, what would I use?

Share your thoughts,


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## Enderman (Feb 19, 2017)

AndyPost said:


> Noob question. I was going to link 3-3s batteries in Series to power 10 of these 100w LEDs. It seems like I'd have to have something to limit the amps to keep the LEDs from frying. If that's true, what would I use?
> 
> Share your thoughts,


A constant current LED driver for COB leds.
You can search for one on mouser or digikey, and sort by constant current.


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