This is another in a series of runtime tests of bike lights.
-
PDW Radbot vs. PB Superflash taillights.
PDW Cosmic Dreadnought vs PB 2W Blaze Headlights.
PB Blaze 1W vs. 2W Headlights.
This time, I’m comparing five taillights, all powered by 2 AAA batteries. 
From left to right, we have the MEC Saturn, PB Superflash Turbo, PB Superflash Stealth, PB Blinky7, and the PDW Danger Zone. All these lights have superbright LED’s and 0.5W or 1.0 W LED’s in various combinations. The list prices range from $9-37. The PDW Radbot 1000 was not tested this time, since after some light use, and then sitting in my garage over the summer, mine seems to be dead.
Here is how the five lights look turned on: clearly on fresh batteries, the Superflash Turbo is the brightest.
Here are the same lights from the side. Even though the Blinky 7 is designed for enhance from the side, none of them do particularly poorly.
Once again, for the purposes of this test, I used rechargeable AAA’s; either eneloops, or the made in Japan Duracells with the white caps that are supposed to be the same battery.
Here are the measured runtimes on steady mode. I won’t bother to list the manufacturer’s claimed runtimes as they are always much longer.
Here is a video, with 1 second = 87 minutes realtime.
Note that the turbo cuts out first. The measured runtime of 3 hours is well short of what I measured last time. The PDW is next.
Here is a still of the lights after 10 hours 40 minutes, taken with the same exposure settings are the earlier side view.
At this point, the three remaining lights are adequate “be seen” lights. The PB Superflash and the MEC Saturn cut out at about 14.5 hours, although you can see in the video that the superflash stays brighter until the very end. The PB Blinky7 is still dimly lit at the time of this writing, more than 25 hours after the start of the test.
There are a couple of caveats here. Firstly, I would expect that runtimes will be longer if you use alkaline AAA’s rather than rechargeables. Certainly this was the case for the headlight test. Secondly, all these lights are more typically used on flash mode. One of these days I’ll have the patience to redo this test with flash mode. Finally, I don’t know why the Turbo did much more poorly than in a previous measurement when it ran for about six hours on steady.
Conclusion? My overall favorite light remains the standard 0.5W Planet Bike Superflash. The 1W Turbo is almost too bright, and it has a much shorter runtime. The DangerZone seems to do better than the PDW 1W Radbot, and so it seems to be intermediate between the 0.5W lights, and the superbright 1W lights. For applications like randonneuring, where flashing is not allowed, an ideal taillight might be 1W with a half power steady mode as an option to extend battery life. An alternative would be to have the PDW Danger Zone with an option to light up only one of the LEDs. The addition of reflective material would also be a plus.
THe MEC Saturn does surprisingly well for a $9 light.
However, I’m not sure how the mount (which is secured by a rubber strap) will hold up over the long run.
Also, MEC appears to have dropped the regular superflash from their website, in favour of the superflash turbo, which is a terrible idea.
With lots of choices in the $9 – $15 range, there is no excuse to be riding this time of year without a decent taillight. Ride safe everyone!
UPDATE: another blog post that complements this one, with lots of information about lights and cold weather performance.
Very good information. All of the relevant issues are addressed. I have the two PB lights, and it’s good to know how much sooner the Turbo flames out.
As for the overkill Turbo, I use it on flash in the daytime for urban traffic: it shows up in anything but direct sunlight, and it is useful for underpasses and the like. I use both PB lights on steady for urban night riding: flash is too annoying. Also nice the two PB lights use the same mount.
For randonneuring or other rural night riding, any of these on flash should be good enough to be seen, or on steady not to dazzle other cyclists. I’d use the Turbo for randonneuring, because a pair of AAA lithium batteries would get you through the night. See link: http://data.energizer.com/PDFs/l91.pdf
great information about the Li AAA cells, especially the discharge curves. For randonneur events, this looks like a good solution. For everyday riding, I’m assuming that most people will use NiMH rechargeables.
Great addition to the series Jun! I’d 2nd the earlier comment about running the brighter Turbo light during the day in strobe to catch the attention of distracted city drivers and for the occasional dark area (don’t forget those shady areas under trees which are super common in most cities).
The lithium AAA cells are much better in the freezing cold. One set lasts me all winter. I only use them in the winter. They are $12 a pop or so, which makes the cost of my PB superflash almost doubled.
I’ve also run a blackburn mars 4? It performed very well.
I’ve found in the country you don’t need as bright as light to be seen, since the ambient lights don’t drown your blinky out. In the city i’d go as bright as possible without being honked at. Either of the lights I mentioned are adequate IMO.
Oh yes, winter. I have run regular batteries, NiCd and NiMH rechargeables, and lithium, down to minus 30C. Lithium have the best tolerance to cold, then in order of best to worst: NiMH, NiCd and regular. At minus 30C you can only rely on lithium*, a dynamo, or batteries kept inside your clothing, which is impractical for tail lights, but practical for headlamps. Flashing also works better than steady in that cold, too. Perhaps because the battery cannot put out the power for steady.
*I have had a headlight lithium power pack mounted on my frame get too cold to put out power.
What I found about batteries in cold I learned from experience that matches the classic handbook: “Mountaineering, the Freedom of the Hills.”
My own post on the same topic, with credit and traffic pointed to you.