Magicshine 900 Lumens Light?

Discussion in 'General Discussion' started by Jubz, Jul 18, 2009.

  1. Jubz

    Jubz Member

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  2. profnachos

    profnachos Member

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    Placed an order a week ago, and it is en route.
     
  3. Jubz

    Jubz Member

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    Great, will be really interested in your f/b, especially how bright it is in the low (4.5 hours) setting.
     
  4. profnachos

    profnachos Member

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    I actually ordered it from a different website. The order was placed on the 11th, and the status is stuck in "waiting for supplier."
     
  5. Lambda_drive

    Lambda_drive Member

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    Orders from dealextreme usually take about a month because they ship them from Hong Kong.
     
  6. GeoMan

    GeoMan New Member

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    They ship from China plus they probably aggregate orders so they hit volume thresholds. All this takes time...

    Thanks for the mention.
     
  7. 92se-r

    92se-r Active Member

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    Probably very bright, but not 900 lumens bright.

    8.4V input? I have no idea how they are getting that from 18650 batteries, which are 3.7V batteries.

    Also, 3 hours of runtime at 2.4A of output current? I don't think so. Also, that LED emitter is dumping 12W of heat out in a very small package. Heat density is very high, and light output varies as a function of temperature. So I highly doubt that small of a package will be able to output 900 lumens.

    Be careful of manufacturer claims on lights. There are a lot of ways to spout PEAK numbers that they can never achieve. But, at this pricepoint, bang for the buck, this light cannot be beat.

    Keep in mind you need to make a custom battery pack or purchase it separately. Deal extreme has good deals on 18650 batteries. I'm planning on making a custom battery pack with some pvc pipe. :)
     
  8. GeoMan

    GeoMan New Member

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    Not so. Ours comes complete with battery pack, charger, etc. - see pics above.

    Also, we've discussed light output with their engineers. They stand by their 900 lumen and run-time ratings.

    GM
     
  9. keoke526

    keoke526 New Member

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    I have and it is very bright compared to the cygo-lite mitycross 350. The o-ring design seems ok, but others have complained of slippage on the trail.
     
  10. GeoMan

    GeoMan New Member

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    It is bright.

    Lupine uses the same o-ring mounting system and, as you know, their "equivalent" model (hard to compare - Lupine is very high quality) is the Tesla 4 at $488 (MSRP, ours is lower). I've used many different mounts and this is the best system, IMHO, for versatility, reliability, and ease of use.

    Any slippage is simple to remedy with a bit of spacer between the bar and the lighthead. Even a bit of old rubber tire tube wrapped around the bar first would suffice. Frankly, I know of nobody who has a problem with mount slippage.
     
  11. Jubz

    Jubz Member

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    No prob. If I go this route, I'd definitely order from you. I've seen your ongoing presence here and over at mtbr.com and always try to support the supportive dealers/folks; it's all about the community.
     
  12. GeoMan

    GeoMan New Member

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    That's how we feel too!

    Thanks, Jubz!!!
     
  13. 92se-r

    92se-r Active Member

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    Whoops, the link said batteries were separate. Sorry.

    Their "engineers" can say whatever they want. I doubt you are even able to talk to the guys that actually designed it. But, it'd be awesome if I was wrong because that would be a great price for a light with such high lumens and run time ratings.

    To the OP, please post your actual run times when you get this.

     
  14. 92se-r

    92se-r Active Member

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    Ok, I took 5 minutes to take a look at Seoul Semiconductors datasheet on the P7 emitter.

    900 lumens is the theoretical maximum output for this LED. This is also achieved at 2.8A. According to Magicshine, they are running their light at 2.4A.

    Typical lumens output according to Seoul is 700 lumens, again, this is at 2.4A.

    Now, another thing that is very important to look at is thermal resistance and relative output vs junction temperature.

    Thermal resistance is 3C/W. This is without any thermal transfer compound or anything, but I'll even leave that out of the equation. At 12W of power, you automatically have a 36C temperature rise from ambient at your junction. Assume that the ambient temperature is 25C, you now have a junction temperature of 61C.

    Now we go to the chart, and it states at 60C, you're already down to 90% output. And this is an ideal case. In reality, your junction temperature will probably even be more than this. So you'd be hardpressed to even hit 630 lumens now.

    In regards to battery life, I'll assume that 8.4V input is a typo. 18650 batteries are nominal 3.7V. The highest AH rating I've seen is 3000mAh. So assume 2 in series, 2 in parallel. I'd say at 2400mAh, you'd get 2.5 hours MAX. Probably more closer to 2 hours.

    Now don't get me wrong, for the price, I want to get one. I can't even build one for that price. However, I find a lot of light manufacturers are very misleading on their numbers and do a lot of theoretical ASSumptions.

    One of these days I need to get off my ass and build a legitimate 900 lumen light with some R2's I have, but even those ratings I don't believe because Cree hasn't even updated their datasheets to acknowledge the R2 bin exists.

    In conclusion, ride the crap out of this light because bang for the buck, this thing is awesome. However, 900 lumens and 3 hours run time, I'm skeptical. Maybe I'm wrong though.
     
  15. Jubz

    Jubz Member

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    Great info, very educational for me re: the numbers and trying to get a sense of this all.

    Here's another light I've been looking at, made by a DIY guy and now selling them, the Amoeba...though now jumping the price up to ~$200 (can get 3 of the Magicshine's for around that price eh). The compact design is appealing. Links to various MTBR.com threads at his blog below. Been thinking about the Magicshine on the bar and the Amoeba (spot version) for the helmet.

    http://amoebalight.blogspot.com/

    [​IMG]

    [​IMG]
     
  16. GeoMan

    GeoMan New Member

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    I certainly give credit to the builder but I have to admit, it's a little Rube Goldberg looking... What is the helmet mount? Velcro? Pricey too.
     
  17. profnachos

    profnachos Member

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    Oh crap. I wish I had known.

    I need it soon as the day is getting shorter. If I cancel the order, and ordered it on your site, would that be shorter? And also how about the batteries? Is ExtremeDeal not including them?
     
  18. GeoMan

    GeoMan New Member

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    We can ship tomorrow to you from the US. Shorter? You decide.

    ExtremeDeal includes the battery, too, as do we. I don't know where that idea came from... The pics tell all.


    [​IMG]
     
  19. 92se-r

    92se-r Active Member

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    the amoebas are nice lights and i actual copied his enclosure. however, the markup is huge. true price should be closer to the magicshine light. velcro works awesome for the amoeba style light on the helmet.

    i think the magic shine is going to put all the other light manufacturers out of business. bang for the buck, it cant be beat. i can make a similar light for the same price, but thats because my labor is free. thats basically my cost for materials.
     
  20. 1080P

    1080P Banned

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    LiIon chemistry batteries charge up to a peak voltage of 4.20 volts. In series, that is 8.4 volts.

    This whole kit comes with a battery pack and charger, which contains 4 18650 Li ion batteries at about 2400 to 2500 mAH each. So it should be good with the set up on high for about 3 or 4 hours if the die is drawing 1700 to 1800 mA @ 7.4 v.

    I have a light with the same emitter, and I'd say that due to heat issues, heat sinking it and dissipation of heat without damaging the emitters, you'd be hard pressed to run it at it's rated 2800 mAH without damaging the emitters.

    It probably realistically lights up at around 400 to 500 lumens after the first 10 minutes of operation, while the battery voltage drops from 4.2 to 3.7v and stabilizes there. I've found that my P7-C class emitter is pretty close to what the old Light and Motion ARC lights put out in terms of lumens. Unless you are extremely fast, 500 lumens is plenty, as near as I can tell. for night riding.
     

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