The evolution of the Amoeba continues - Cree XP-G2
Got some of the newest Cree XP-G2's mated up with some Ledil Regina reflectors in one of my Amoeba's. Powering it with a B2Flex I had lying around.
Can't wait to get out and test it out on tomorrow mornings ride
nice! I was just thinking about Amoeba lights the other day, wondering what you were up to, and now I know
I'm really interesting to hear what you think re. brightness and beam shape compared to XP-G and XM-L lights at the same current. What tint did you get BTW?
another Q - what cells do you use in your lights? Tried out the NCR18650Bs yet?
Last edited by mattthemuppet; 08-23-2012 at 11:55 AM.
Reason: another Q
Hey Matt, yeah things slowed down quite a bit during the summer. Kept busy building lights for people doing 24hr events. Now that days are getting shorter, things are getting crazy again. I got the XP-G2's in the 1C tint. I use 2600mah Batteryspace packs (always have) and have never had a problem. I still use my original packs for my personal lights that I purchased over 4 years ago, still come off the charger like they are brand new. I think they are using Sanyo cells, but not for sure.
adrenalnjunky - yes that is a PG-7 gland
yeah, you must be bonkers busy making lights this time of year! Interesting about the batteries - I guess reliability and continuity are more important than outright capacity, especially as the voltage settings would probably be different due to the different discharge curves of various li-ions.
Looking forward to some comparison beamshots!
Looking good scar
Originally Posted by scar
Two XPG2`s and two Cells married to a B2flex
How are you finding the regulation and runtime.
I have just fitted 4 XPG2`s in a b2flex light and will be using a 4 cell pack .
at 1.5 amps the VF was 12.4 cold and dropped a bit as the leds warmed up .
it starts to drop out of regulation at about 14 volts and dims a little then dime some more at 13 volts this is at the full 1.5 amps
VF @ 1 amp was 12.2
matt - Sorry, no test run reports just yet. Our morning ride on Friday morning turned it an adventure of trail finding in which we were carrying our bikes the majority of the time. The helmet light was focused on the ground directly in front of me. Hoping for Monday morning.
trout - yes, I did find the same thing with the 2 LED/2 cells on a B2Flex early on. I have been using LFex's for quite awhile now. I just had the b2Flex lying on the bench for quite awhile and thought this would be a use for it. Max measured output of the b2Flex is 1300ma's on fresh batteries.
Looks good Jay! If you need someone to test them out for you, I'd be more than happy to give them a go .
What are the main differences between the XP-G2 and the XM-L in terms of lumens and beam pattern? I'm still totally digging my XM-L on the bars but I would slowly like to upgrade my old head mount to something with a little more horsepower.
Hey Kristian, sorry I am just getting back to you, was in a training class for work until late today and had to get my chores out of the way before sitting down at the computer.
They are pretty close to each other in lumen output when run at the same input level, but the XM-L's can take much more input, they can take 3.5 amps with the proper heatsinking. My housing can't take that much, I run the one you have max at 2.0 amps. The XP-G's can handle 1.5 amps and I thought I read that the XP-G2's can handle 2.0 amps. I run mine max at 1.5 amps.
The XM-L is definitely more floody than the XP-G's and XP-G2's. The one I have pictured is the 2x XP-G2's and it is a sweet set-up for the helmet. A crazy amount of light from a very tiny package. I can also do a 3x XP-G2 version for the helmet to get a little more punch.
The new XP-G2's are a not a huge increase, but they are brighter (the rated 20% seems about right).
I am still planning on being down at the 24hrs of COS, I will bring some goodies for you to check out
Trying to get to bed so I can meet up with my FIFO bro's at 4:30am up at Centennial Cone. Should be a great time
I'm looking forward to seeing them in person!
Scar, any narrower beam with XPG2?
scar - do you ever run into heat issues? I know you usually keep to a 2x LED setup in your lights. I'm building a 6-up XP-G2 light in a similar sized housing.
I can take a stab at that one... I build a 6-up XPG/XPE and it all depends on what you mean by "issues." If you want to have 1000+ lumens for any length of time with no air flow, then yes, you're going to have issues. I have a similar sized housing with major heat sinking surface area (>30 sq inches) and can run about 13 watts continually with no air flow for about 4-ish minutes before I trip the 60 degC safety cut-back limit on the controller board. I chose this value based on the need to keep the estimated LED junction temperature below the factory recommended maximums.
Originally Posted by adrenalnjunky
So the answer is it all depends... If you're building this light for yourself and you understand the limitations, conditions for safe operation, and potential dangers, then yes, you could get away with cramming that much power in that small of a box with no additional heat sinking. A good amount of air-flow and excellent thermal coupling between the LEDs and housing would definitely be required.
If you're going to be building the light for someone else, then you really have to consider worst case scenarios, like running with no air-flow. The controller, in this case, would absolutely have to have some aggressive protection circuitry to prevent overheating.
Nah - this is for me, and really it may not be my "every nite ride" light. I have a couple of more reasonable XM-L builds coming together too that will probably be my go-to setup.
I just wanted to build something with a ton of output just to see how it comes together.
For my effort, most of the locals aren't interested in spending the $$$ for me to make them something really nice. I don't want to support them down the road anyway. I've been sending them the $50 fleabay Mgicshine XM-L clone route, and then going through the lights when they come in to verify decent thermal coupling and solder joints and such.