Nitehawk K2 emitter questions for those that own it.
 

I'm curious is there a way to up the battery life in the light? Is the regulator in the battery or in the light unit? Perhaps James could weigh in on this?

This is the Nitehawk K2 Emitter light for those wondering. I understand it comes with a 4AH battery. For those that are technical/electical do you know if you can use a Li-Ion battery with the K2 if it's regulated to 6V? http://www.batteryspace.com/index.as...OD&ProdID=3236 That is the battery I'm thinking of using if I went Li-Ion.

Or use this 6V 10AH battery if I was to go with a NIMH solution.

Ok, just found this info out directly from Nite-Hawk's R&D dept. The regulation unit is in the head unit and NOT the battery. Makes sense to me but I had to ask to make sure because it would not make much sense to throw out the battery and the reg. board to get a new reg board and battery each time the battery dies.

Also you can use the Phienox (sp) battery for longer runtime as they have told me. You just need to buy the new charger for that battery. Having been given that information that means that if the stock battery ever went south on me I can always make my own battery pack or buy my own new battery pack and get a batteryspace nite-hawk adaptor and I'm in busienss for longer runtimes. Booyah!

Not sure if this is related to your question, however a fellow BF'er by the name of Waytoomanybikes (not to be confused with 2manybikes), boughtthe Dual K2 Emitter and was very impressed with it. He posted a review with photos a while back when this section was in the Commuter forum.

Well the battery will eventually die out thus the reasoning to ask about that. Now that I know the reg board is in the light head I can always up the batteyr size for night riding and carry the stock as a spare.

Think you can help double the effort to find that post Waytwomanybikes posted?

Thanks.

I have been looking for a better light than my old Specialized Astro 5 (which dropped dead on me recently) for occasional, recreational night riding. I looked into building my own using various MR16 halogens, then started looking into LED.

After looking at some Luxeon datasheets I purchased a flashlight that used the Luxeon III emitter mounted on the star heatsink. They claim 70-80 lumens, and I believe it. I'm throwing away all of my AA, C & D cell halogen (krypton and xenon) flashlights, and replacing them with these little wonders. I sent my daughter to Girl Scout camp with one and two extra sets of batteries (3 AAA cells). Remarkably, she came home with the original set still in use. She claimed to have used it for an hour or two each night, and her light was the talk of the camp.

I am thinking of modifying two heads for bike use (near - wide spread, far - narrow beam), and driving both with one external battery pack. 6 watts of power, 150 lumens out in two patterns. The reason I bring this all up is that the claims made by NiteHawk sound a bit overly optimistic.

The K2 emitter is a step up, but not that much. At max rated current (1500ma - about 5 watts input), it is good for 140 lumens or so. That is terrific (around 30 lumens per watt), but in no way would it compare with a 20 watt halogen. I would think you should be able to get around 350 lumens out of a 20 watt halogen. Plus, the beam pattern they show in their product sheet looks pretty narrow - almost pencil beam. Wonder how well it would really work as a bike light.

Yes LED technology has advanced quite a bit the last few years. I mean now a days we have Cree and Seoul LED's that give 240lm max and ~90-110lm min. which is amazing because you have the light of a LuxIII but running at 1W. :D More light, less power, go-go-go!

Yes I know Nitehawk is a bit overly optimistic on thier lighting claims. I mean the AL-X is rated at 400lm and they say it's equivlent to a 10W halogen. Err.... with the 2007 AL-X (I've noticed a beam change from the old models and the beam is wider for more spill) with the little more spill the spot is less hot so how can that really be a 10W halogen? It's more like a 5-6W halogen realistically considering they canceled the Digital AL-X with the power regulation which they only supplied MEC with but canceled it due to thier explaination that it's basically the same as the NiteHawk K2 in features but with a 1W LED. What about that 400lm? Was the tester locked in dark room for a year before making that spec? Are you telling me the AL-X is in the same league as the Planet Bike Alias which is rated at 10W HID @ ~500ish lm? ( Welch Allyn 10W HID specs) Yah right...

Actually the spot on the NiteHawk K2 is more for the helmet for lamping things as you turn the corners. Dispite the inflated specs on the AL-X it makes a good to-see back-up light that is very light weight and take take 4xAA batteries but you'll jus ride slower but it'll take you home.