Advice on DIY area/flood light please :o)

[Dangerboy]

I'd like to build a simple and cheap area light for my garage.
I was thinking of using primary c-cells in battery holders and star-mounted XR-Es- I'm sure I've seen this done somewhere before on here.
Stupid question, but what are the min/max number of batteries I'd need to power 2 XR-E's in series?
Many thanks,
Adam

 

[bluecrow76]

If you want it for your garage, you could use Xitanium or other 120V drivers instead of batteries. The number of LEDs and drive current depends on which model you order. I just ordered some smaller ones from Future Electronics. They're on the FedEx truck to be delivered today! Yeah!

 

[Dangerboy]

Good idea, but alas, there is no power to the garage, hence the need for battery powered area light.

Thanks anyway though

 

[TigerhawkT3]

You might want to consider going with 12V SLA instead of alk (I'm guessing) C cells. Just hook up four Crees in series, and it'll DD nicely, at about 220mA.

If you really want to use alks, you'll probably need a driver. Try one of these, with 8C and a pair of Crees, or 12C and three Crees.

 

[abvidledUK]

I built a light for similar purpose.

Plastic box, small 12v SLA battery, reversing light screwed onto box, switch, 12v socket for charging from car charger.

Worked a treat for several years.

 

[bluecrow76]

Second what they both said. I built a little light on a box (posted about it here) a while back. I used the same driver from Kai and 6V or 12V SLA batteries to run it. It is currently my night light. Nothing fancy but it serves its purpose.

 

[J_C]

I'd like to build a simple and cheap area light for my garage.
I was thinking of using primary c-cells in battery holders and star-mounted XR-Es- I'm sure I've seen this done somewhere before on here.
Stupid question, but what are the min/max number of batteries I'd need to power 2 XR-E's in series?
Many thanks,
Adam

It depends on the method you use to drive them (regulator board vs resistor(s)?) and your target output (current they receive).

I happen to have an extracted XR-E curent:voltage graph so I attach it. If using 2 or more LED in series just sum their total forward voltage drop for a bare minimum required voltage (which you'd do towards the end of the battery pack lifespan, the voltage at that end of life to assure you get reasonable runtime from them).

 

[TorchBoy]

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