DiY LED Grow Lights with CREE CXA3070 COBs and CPU Coolers


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Easily build your own high-power LED Grow Light using COBs!

(Built with assistance of RIU contributors! - Original thread )

Battlestar Ganjatica - A 480 Watt Multi-Mode LED Grow Light

6x CREE CXA3070 @ 3000K - $36ea ($216)

2x CREE CXA3070 @ 5000K - $38ea ($76)

8X Meanwell LPC-60-1400 Drivers - $20ea ($160)

8 Arctic Cool CPU Coolers - $9ea ($72)

Rhino 12v External HDD Power supply - $9 (for powering fans)

1 Tube Thermal Adhesive
- $8

3'x1' White Shelving board - $10

4x Bottom Sliders for Drawers - $7ea ($28)

(link is not exact model. I only paid $7 each in-store)

3x 2-way Switches - $4ea ($12)

4 heavy-duty stainless eye bolts - $1ea ($4)

10 Pack In-sure easy wire connectors - $2

6-Pack Blue Mid-line connectors - $2


MISC Other Materials:

Misc materials:
Prolimatech PK3 or similar (eBay)
Kapton tape (eBay)
Zinc chain (Walmart or Amazon)
50V hookup wire for LED string 18ga (or use 600V wire from old xmas lights) (elecdirect)
600V wire for AC connections 18ga (elecdirect)
slide connectors .25" (bare, crimp on) (
heatshrink tubing .25" (
Solder 63/37 lead (amazon)
Solder flux gel syringe - MG chemicals ($10 eBay/Amazon) (this really helps)

tools needed:
cordless drill (harbor freight $15)
heavy duty crimper/cutter/stripper (walmart ebay amazon)
soldering iron (60w eBay $10)

GFCI (eBay $7)
sand paper to lap heatsink surface (3M home depot)

Ignore the fan-speed controller. Didn't end up using it.


Wiring is pretty basic. Just scale up the below diagram (provided by RIU member Goud)


And here you go!

3 Modes: Veg, Teen, Bloom

Preliminary Results look good!

First day over plants:

Week or so later:



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Thats a nice set up!!! How was the yield with it? And whats the wattage of those cobs compared to what youre running them at??


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CXA3070 Spec Sheet

I run mine with 1400mA CC drivers

I took Goud's expert advise:

View attachment 2990324

minimum Vf for 1400mA at 25°C --> 37.5V
at 85°C about 36.8V

the Meanwell driver can deliver up to 42V
I will post yield after the final cut. The current grow still has 3-5 weeks left. Unfortunately this round is not a good benchmark, since the plants were started under a pre-made panel and had 2 weeks early-bloom assistance from 400 watt of T5HO. The last 2 photos in the post show the difference only about a week made in bud growth though!


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Looks good either way. are there lenses on the lights as well?? The LEDs i use dont have any. They use epistar or bridgelux LED cobs so not tip top of the line but a good quality none the less.


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i'm looking forward will you start from clone next time?
Yeah I have a lovely bubba kush momma in my veggie bin for the next round.

Looks good either way. are there lenses on the lights as well?? The LEDs i use dont have any. They use epistar or bridgelux LED cobs so not tip top of the line but a good quality none the less.
No lenses, as they just diminish the output of the COB. Reflectors can help, but I like the default spread just as it is.

I will be adding 6 deep-red Luxeon LEDs on individual flexible arms soon, and these will mount on the Battlestar for bud-targeting.


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About time lol

Got lots of pop corn, beer, and weeeeeeeeeeeeeeeeed

If the info I just came across is accurate, make room for 1-2 10K+ cobs

I just read that 10K during flush amps up tric production.

I am within a few days of harvesting 2 sweet WH x WW pollinated with BGum under my 432w hot5. Same strain but small pheno grown under my leds is drying now.

On that advice. I just replaced 3 hot5 tubes with 6500s (his fall back position)


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figured just didnt knwo if the pictures were hiding some of the lenses.

I like the lack of lenses on my panels as well. You should be able to get them within a few inches of your plants give or take. I just had my first burn problem when my plant ran into the light because of the flower stretch. haha


This picture makes it look like you built an airship. Nice.

Can you program the fans to keep it in a stable hover? You could ditch the cables.

You would need such high powered fans to keep it up it would damage the canopies probably. :P


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Anymore updated Pics or Reports on Grow with these, Any issues you have noticed? Temps of GR, around ladies and such.

Quick Question: Them COBS are they 60w each?

That's some Mad Skills Gaius..



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Nice! would love to build one "BATTLESTAR GANJATICA" bit out of my price range at the moment...

So the 480w is like 8 x 60w...might look into the 30w version and price up the components for a slightly smaller(PWR) build.

Great build...n looking sweet!



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Thats amazing. These cree cxa3070 are the biggest and baddest led chips right now, right? Did a little reading and something like 138 lumen per watt.


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The CXA3070's are pretty much the most powerful/efficient COB's that the retail shopper can get their hands on. But the highest bins are often unavailable. I just bought a couple of 5000K CXA3070's. Had to settle for the CXA3070-0000-000N00Z450F because nobody's offering the higher bins. Not to the person who wants to buy 2 or 3 of them.

You have to be careful about lm/watt. They're more efficient when they're not being driven hard. You can get more light out of the device by driving it harder, but you're losing efficiency as you crank up the amperage. So it's a story of diminishing returns.