using cree torches instead of bicycle lights

Mr_Cellophane

I use these to mount my torches at £1.19 free P&P

http://cgi.ebay.co.uk/Bike-Bicycle-Flas ... 3a534a043c

2tired2ride

Do you guys use Rechargeable batterys in your Fenix/cree lights?

FeynmanC

I've got the fenix L2D and use 2900 rechargables. It would go through a new set of duracells in less than 2 hours, not even using turbo mode. The rechargables last for at least 3 hours and i've already recouped the cost after only a couple of weeks, including the intelligent charger!

Headhuunter

FeynmanC wrote:

I've got the fenix L2D and use 2900 rechargables. It would go through a new set of duracells in less than 2 hours, not even using turbo mode. The rechargables last for at least 3 hours and i've already recouped the cost after only a couple of weeks, including the intelligent charger!

Yep, I use an L2D with anything from 2500 to 2700 mAh AA batts charged on the intelligent charger and so far no complaints, although as someone has pointed out, torches aren't as visible from the side, however are amazingly bright from the front. The L2D reflects off signposts and car reg plates 200 odd metres away at full power

FeynmanC

Road signs were flashing IN THE DAYTIME when I went out on an overcast day a couple of weekends back!

Very strange lol

Northwind

Headhuunter wrote:

The L2D reflects off signposts and car reg plates 200 odd metres away at full power

Ironically, this isn't so much because they're bright, it's because they're throwing a fair amount of UV- you get the same with HIDs. It can be pretty useful but it's not a very good judge of light capability. I suppose you could say it's actually an inefficiency since some of the light's energy is in non visible wavelengths but that'd be a bit of a push.

Headhuunter

Northwind wrote:

Headhuunter wrote:

The L2D reflects off signposts and car reg plates 200 odd metres away at full power

Ironically, this isn't so much because they're bright, it's because they're throwing a fair amount of UV- you get the same with HIDs. It can be pretty useful but it's not a very good judge of light capability. I suppose you could say it's actually an inefficiency since some of the light's energy is in non visible wavelengths but that'd be a bit of a push.

Interesting, I've always thought the light from LED lights is much bluer than normal ones, however I don't really see why UV light would particularly be visible reflecting from street signs and car reg plates - Neither of them is flourescent in colour (like high viz which reflects UV at dawn and dusk) and in any case our eyes can't see UV so surely if it's UV, I wouldn't be able to see it. Genuinely interested BTW, not trying to pour scorn over your comment.

cougie

FeynmanC wrote:

Road signs were flashing IN THE DAYTIME when I went out on an overcast day a couple of weekends back!

Very strange lol

Is this with the lights on the bars or on the helmet ? I find stuff reflects back from miles away if i have my helmet light on - less so if its on the bars.

I'm confused about the UV thing.

Mr Sworld

cougie wrote:

I'm confused about the UV thing.

Yeah, so am I! If they gave off that much UV radiation then there would be loads of warning notices plastered all over them! Also how would you see the UV reflection as human eyes don't see that far into the spectrum?

Some of the metal halide lamps we use at work do kick out UV at quite high levels but come with dire warnings about only striking them up inside their designated housings (which have UV absorbing optics in them).

So I think it's a bit of urban legend going on there!

snailracer

A bit OT but not completely irrelevent, what is the point of HID car headlights? Are they brighter? If they are, then why don't we just use more powerful versions of "normal" halogen headlights, readily available and cheap?

Northwind

Mr Sworld wrote:

Yeah, so am I! If they gave off that much UV radiation then there would be loads of warning notices plastered all over them! Also how would you see the UV reflection as human eyes don't see that far into the spectrum?

Best real-world example of this i can think of is laserquest Though you can see this in other places, nightclubs sometimes. Cyberdog in Camden, or the glowing rocks section at the Natural History Museum... Shine a UV light onto blue jeans or a white tshirt, or your teeth, in the dark and see what happens. Tron! The levels of UV needed to make this happen in dark conditions are very low because what you're seeing isn't the UV, it's the reaction of the material to UV. Can't remember what it's called, phosphorescence?

Snailracer, A 35W HID in the right colour range can be brighter than even a very bright halogen. But I think the reason they've caught on so much as OEM-fit is that they're easy to package- a conventional halogen needs a big reflector to work well while a HID can be in a much smaller projector, which is easier to design around and more tolerant of funny shapes. Still, I have a 35W HID in one of the headlights of my motorbike and it alone is far more effective than the 2 Osram Nightbreakers I used before, which at the time were the best Halogens available for H4.

(and also, people think they look good- a lot of the HID retrofits people use in cars are in such inappropriate colours, they actually make less usable light than a cheap halogen, but people like the purple light...)

spacedraptor

I have just bought two Cree lights the first is a 900 lumen wide zoom light the second is 300 lumen i use both on the trail the second 300 lumen is a more foused beam so i can scout the trail ahead, the first light casts a wide beam for what is in front of you, very safe on trails & i bought both lights for £39.98 inc postage spare batteries & a double battery charger. that price wasn't each it was for the lot £39.98.

My advice buy some. Great lights better than spending £300+.

Zachariah

I got a torch from DX - have a look at the user pictures further down the page, the three bike ones are mine. It is amazingly bright, and the whole package including holder, two batteries and charger was under £40.

I yearn to one day use the strobe function to save a damsel in distress. It's painful to look at for even a second (the strobe, not the damsel).

Mr Sworld

I have gone back to using alkaline batteries in my Fenix. Tried using Li-ion but it knackered the cells, two different sets started producing gas and now won't charge at all!

alfablue

Mr Sworld wrote:

I have gone back to using alkaline batteries in my Fenix. Tried using Li-ion but it knackered the cells, two different sets started producing gas and now won't charge at all!

What Fenix is that? L2D? NiMH is the way to go, these will supply consistent output for 90% of the charge, alkalines start to lose output immediately and will be at 50% in half the run time.

I use Vapextech 2900mah NiMH, £4.95 inc delivery, and I use a smart charger (must be a smart charger or you cook the batteries). I get 2+ hours runtime on Turbo.

Mr Sworld

I think that Fenix expects to see 1.5V on each cell not the 1.2V that rechargeable cells produce.

alfablue

Mr Sworld wrote:

I think that Fenix expects to see 1.5V on each cell not the 1.2V that rechargeable cells produce.

NiMH will produce about 1.4v which drops to 1.25v for 80% of the runtime, but they will provide much better performance in high-drain applications like lcd torches. Alkalines only output 1.5v at the very start and output continues to decline through the runtime. See the runtime graphs here, you will see how poorly alkalines perform in comparison. You may be surprised



Re: NiMH

NiMH cells are not expensive, and the voltage and performance is similar to primary alkaline cells in those sizes; they can be substituted for most purposes. Although alkaline cells are rated at 1.5 volts and NiMH cells at 1.2 volts, during discharge the alkaline voltage eventually drops below that of NiMH. NiMH batteries offer a flatter discharge curve, particularly at higher current draw.[24]

NiMH cells are particularly advantageous for high current drain applications, due in large part to their low internal resistance. Alkaline batteries, which might have approximately 3000 mA·h capacity at low current demand (200 mA), will have about 700 mA·h capacity with a 1000 mA load.[27] Digital cameras with LCDs and flashlights can draw over 1000 mA, quickly depleting alkaline batteries. NiMH cells can deliver these current levels and maintain their full capacity.

http://en.wikipedia.org/wiki/Nickel-met ... de_battery

Re: Alkaline

The nominal voltage of a fresh alkaline cell is 1.5 V . . . the average voltage under load depends on discharge and varies from 1.1 to 1.3 V.

http://en.wikipedia.org/wiki/Alkaline_battery

So, for these LED flashlights, NiMH is the obvious way to go!

Headhuunter

Mr Sworld wrote:

I think that Fenix expects to see 1.5V on each cell not the 1.2V that rechargeable cells produce.

I have used normal alkaline Duracells in my L2D and NiMH rechargeables. The torch brightness is the same when both batteries are freshly inserted but it does seem to be true that the alkalines decline slowly, dimming bit by bit over their lifetime, whereas the NiMH will suddenly dim. I usually find that even dimmed they provide enough brightness to get you seen on the road and I just change the batts when I get home.