steverosburg
Newly Enlightened
- Joined
- Jul 26, 2010
- Messages
- 21
@swhs: I see that you've posted run times on your site. Looks like the light is exactly as-advertised with the 2 hour run time. It must be drawing ~0.6A per LED, which would definitely seem to indicate more than 270 lumens total, since a single Luxeon Rebel at 0.6A should be close to 200 lumens.
On the other hand, the Supernova Airstream should be powering the XP-G at 1A (based on the 2.5 hour run time using a 2500mAh 18650). At 1A, an XP-G R5 should put out almost 350 lumens (data sheet indicates 347.5 at 1A, Supernova claims 370 lumens), so the values are mostly real and not too much fantasy.
Dollar for dollar, the Philips light definitely looks like the way to go. However, I think the Airstream has a bit more practical range of settings (1A, 750mA, 350mA), which should translate to 347.5, 280-ish and 139 lumens. You mention that the Philips light can be too bright in some cases, but on low (20 lux) it would be under 100 lumens total and a bit low for my liking (unless I were in an urban area which already had considerable ambient light and I just wanted to be seen). I definitely need more than 2 hours of runtime, as I usually do a 2.5 hour ride before work and leave my house about 1.5 hours before the earliest light of dawn (and it will only get worse as winter approaches). That's just cutting it way to close for a single set of batteries, and I'd prefer to not have to stop if it can be avoided. The big outstanding question for me is still whether the Philips light can be charged via the USB port while it's on, then I could hook up one of these and coax some additional run time out of it: http://www.batteryspace.com/battery...ndbeltcliponoffpowerswitch-rohscompliant.aspx.
On the other hand, the Supernova Airstream should be powering the XP-G at 1A (based on the 2.5 hour run time using a 2500mAh 18650). At 1A, an XP-G R5 should put out almost 350 lumens (data sheet indicates 347.5 at 1A, Supernova claims 370 lumens), so the values are mostly real and not too much fantasy.
Dollar for dollar, the Philips light definitely looks like the way to go. However, I think the Airstream has a bit more practical range of settings (1A, 750mA, 350mA), which should translate to 347.5, 280-ish and 139 lumens. You mention that the Philips light can be too bright in some cases, but on low (20 lux) it would be under 100 lumens total and a bit low for my liking (unless I were in an urban area which already had considerable ambient light and I just wanted to be seen). I definitely need more than 2 hours of runtime, as I usually do a 2.5 hour ride before work and leave my house about 1.5 hours before the earliest light of dawn (and it will only get worse as winter approaches). That's just cutting it way to close for a single set of batteries, and I'd prefer to not have to stop if it can be avoided. The big outstanding question for me is still whether the Philips light can be charged via the USB port while it's on, then I could hook up one of these and coax some additional run time out of it: http://www.batteryspace.com/battery...ndbeltcliponoffpowerswitch-rohscompliant.aspx.