PDA

View Full Version : K2 Battery life?



Black Gas
07-02-2007, 04:12 PM
What is the anticipated 4 AA battery life of a k2 (white) running on a 1 ohm 5w resister?

How about with the 2500 mah nimh battery pack?


curious what i'm looking at here...

Hasid Lafre
07-02-2007, 04:14 PM
Prolly in the range of 2 hours or so.

Black Gas
07-02-2007, 11:29 PM
hmm.. for both of them? if they pull 1500 ma, then the 2500 mah should give 1.6 hours, right?

How about the regular duracells?

Hasid Lafre
07-03-2007, 12:35 AM
Should be around the same area maybe a bit more.

Dregan
07-03-2007, 08:58 AM
Depends on the AA battery - I've seen some as high as 2800mAh, even higher if you count exotics like Lithium non-rechargables...

Learn to love the 18650 battery. You can direct drive a K2, no resistor, for mondo time. My outdoor lights run this setup.

Black Gas
07-03-2007, 12:19 PM
Really? I didn't think 3.7 batteries could run something with a 3.85 fv...

If it works, it sounds tempting -- a single small battery, no resistor, getting the same or better effect as 4 AA, and rechargable.. Looks like it would work with most of the LEDs offered here and eliminate the need for resistors, and free up a bunch of hilt space.
And a person can just wire like 4 together if using a board, and get the 8800 mah..

What's the catch? Is the k2 as bright as it would be using a stronger voltage battery?



I'm surprised they aren't carried in the store.

xwingband
07-03-2007, 12:53 PM
3.8V is a typical forward voltage ALSO that's not the minimum to light. It's hitting just about the right voltage that even if it's a few decimal points above the LEDs actual voltage that it will do fine.

The catch is it only works well for some LEDs and it's only better if you were comparing to a resistor. Like if you picked 4AA rechargeable and say a driver like the konlux for the a K2 or buckpuck for a III they're 90% efficient and it's not comparable.

So if you were going small and unregulated on the current, sure! Use a li-ion.

Tim is going to carry li-ions sometime soon. He said he was going to have 3.7V packs and 7.2V stick configs (good for a V).

Black Gas
07-03-2007, 05:55 PM
This would be the proper konlux, right? Looks like it can just fit snugly into 1/4 tubing.. still looking for a US source for it..

http://www.dotlight.de/shop/product_info.php/cPath/100_108/products_id/829

Novastar
07-03-2007, 07:59 PM
Really? I didn't think 3.7 batteries could run something with a 3.85 fv...

If it works, it sounds tempting -- a single small battery, no resistor, getting the same or better effect as 4 AA, and rechargable.. Looks like it would work with most of the LEDs offered here and eliminate the need for resistors, and free up a bunch of hilt space.
And a person can just wire like 4 together if using a board, and get the 8800 mah..

What's the catch? Is the k2 as bright as it would be using a stronger voltage battery?A 3.7v Li-Ion will absolutely run a K2 or Lux III given that the fwd voltage is close enough. Li-Ions tend to meter higher (4.2v) and maintain voltage over their life cycles. Additionally, you have to simply measure the amperage that is being spit out by a driver or whatever setup to figure on if your LED will be as "happy" as it can be...

A "light side" K2 LED wants 1500ma. A "dark side" K2 LED wants 700ma. An FX board will spit out about 800ma when all is said and done for the LED... and Corbin's spits out an even 1A. Erv's is programmable so that you can suit the juice to the LED's needs... and same with Alex's board--if and when it comes out.

A resistor is a tougher deal, as you'd probably want to get as close to the LED fwd v as possible (so 4.2v is good for 3.85 fwd v), and resist as little as possible. In some cases... you won't even need a resistor.

xwingband
07-03-2007, 08:12 PM
This would be the proper konlux, right? Looks like it can just fit snugly into 1/4 tubing.. still looking for a US source for it..

http://www.dotlight.de/shop/product_info.php/cPath/100_108/products_id/829

Yup, if you were dead set on maxing the LED and not going for any of the fancier lightsaber specific drivers that be the one to go for.

With shipping and VAT it'd be more, but again if you were dead set I guess it's not that bad.

Novastar
07-03-2007, 08:21 PM
Just remember, match the driver output with the LED max cont. current. Some LEDs "want" 700ma, some want 1000ma, some want 1500ma. You'll notice:

LUX III "dark side" = 1540ma
LUX K2 "light side" = 1500ma

LUX III "light side" = 1000ma

LUX V "light side ONLY" = 700ma
LUX K2 "dark side" = 700ma

So... you have to simply watch for what it is you want to give the LED. Granted--most LEDs aren't going to be all THAT bad if you undercut the driving a bit. Running an LED that wants 1000ma at 800ma won't make much of a visual difference at all. However, running one that wants 1500ma at 700ma... probably will. :)

Dregan
07-05-2007, 12:37 PM
This would be the proper konlux, right? Looks like it can just fit snugly into 1/4 tubing.. still looking for a US source for it..

http://www.dotlight.de/shop/product_info.php/cPath/100_108/products_id/829

If you want a straight driver like that, look for a buck puck, from LEDSupply.com or Luxeon.com, as the $20 US should still be cheaper - or even one of the mini-drivers that were discussed in the New Tech forum a while ago. The latter are a bit of a pain to solder, but at <2$ US each, including shipping, I'll take that. I've got ~60 left of the 350 mAh from my last 500 pc order (not so good for saber building) but for price and size, you can't beat them.

gundamaniac
09-27-2007, 11:04 AM
Isn't the highest rated buckpuck out there only 1000mA? How would that affect a green k2 that wants 1500?...

And that's an interesting note, nova, that the FX puts out about 800mA...which would sort of explain why my new k2 looks about the same as the luxIII I had in there before....

Strydur
09-27-2007, 11:09 AM
If you want a straight driver like that, look for a buck puck, from LEDSupply.com or Luxeon.com

Or better yet you could just buy them here since we sell them :?

gundamaniac
09-27-2007, 11:13 AM
lol. Hi Tim!

What's your thoughts on driving a light side K2 off of a buckpuck? Of course I'll order it from you if it turns out to be a good choice for the K2.

Also...using rechargeable batteries, I can only get 4.8v, not the 5v minimum that the buckpuck says it needs...

What i'm really looking for is some kind of increase in brightness to justify switching from my green luxIII to a green k2.

Hasid Lafre
09-27-2007, 11:23 AM
Well i would take the 1000 and 700 pucks and wire them togeather to get a 1700 puck and use that for a k2.8)

gundamaniac
09-27-2007, 11:49 AM
Yowza. i don't even have close to that kind of room in my hilt for two buckpucks. I might, just maybe, be able to cram in one.

Hasid Lafre
09-27-2007, 11:52 AM
I dont think there that big. considering the 350 puck is no bigger than the head of a pencil.

gundamaniac
09-27-2007, 11:57 AM
I've got one buckpuck. It's not that big, true, but it does take its fair shareof space. And as it stands, I'm using up nearly all the room inside my saber already, without any pucks in it. So two buckpucks is entirely out of the question :?

Hasid Lafre
09-27-2007, 12:16 PM
Well that sucks. but eather way the k2 will be ran quite nicly with just a 1000 puck.

gundamaniac
09-27-2007, 01:30 PM
is there any way to run the buckpuck off of the MR board, so I don't need to wire it to teh battery and to a DPDT switch?

And maybe, in doing so, be able to combine the MR's output with the buckpuck's output for a combined higher output?

Onli-Won Kanomi
10-13-2007, 03:13 AM
I saw that the K2 kits sold here come with a 4 AAA [not AA] battery holder so I ordered that with my K2 white and K2 royal blue LEDs since there dont seem to be any rechargeable battery packs in stock at the moment.

I'll be using an Ultrasound driver on K2 setting...what kind of battery life should I expect from 4 wee alkaline AAAs???

Jay-gon Jinn
10-13-2007, 09:01 AM
Not very good, Onli-wan...I use that set-up in my US powered saber, and they run it for less than an hour before the blade starts to dim.