I recently picked me up some 1AA lights and thought I'd share the run time graphs of them and comments at the bottom. All were tested with freshly charged AA Eneloops and in my light-box setup. It might not be the most scientific but should be fairly accurate when compared against each other. There is no run time graph of the Fenix LD15 on medium because it only has a high and low and the Romisen RC-G2 is just a single mode light.
EagleTac D25A mini - XP-G, S2
Olight T25T - XP-G, R5
Olight i2 - XP-G, R5
Fenix LD15 - XP-G R4
Romisen RC-G2 - XP-G R4
On high, the Fenix LD15 was the most efficient with the Olights and D25A coming in within 10% of the LD15. The Romisen came in about 70% as efficient as the LD15. Of note is boost mode of the D25A when first turned on which is 20% higher for 90 seconds.
As far as medium mode goes, the EagleTac D25A has an excellent, efficient run time graph and its efficiency even better than on high which is what you expect. However the Olight i2 was disappointing to see that it's efficiency dropped quite a bit at medium compared to high.
Of note is the fact that the Olight T15 high and medium are about the same level. The reason for this is that the T15 head is the same as the T10 head and the low-med-high spacing was done with the 3v CR123A battery in mind. Thus the AA battery can't deliver the output on high and so it almost directly overlaps the medium mode. With the Olight T15 you basically have a 2 mode light. Thus I also have the T10 tube.
Final comments:
There is a little fuzz on the graph of some of the lights and though the eyes cannot see it, the meter does pick it up. I was sampling at once every 4 seconds. The D25A had a rock solid output until the battery finally ran out of juice. I was rather impressed with the D25A. I liked the spacing of the modes and its efficiency. I also like the Olight i2 because of its mode spacing and because the head is easy to twist to change modes along with it's good beam pattern. But was very disappointed in the efficiency at the lower level. My only complaints with the Fenix is the fact that it starts out on high rather than low and the fact that it doesn't have a medium mode. Also I wish that it twisted a little easier when changing modes. But I do like its size, look, beam pattern, and efficiency. I did like all the beam patterns of all these lights.
The Romisen RC-G2 had a nice neutral tint and beam pattern, but the efficiency wasn't as good as the rest. It resides as my kitchen utility light because its an inexpensive light that basically does the job. In fact, the Olight i2 on medium mode had about the same efficiency as the RC-G2............which was about 56% as good as the EagleTac on medium.
I place a lot of emphasis on a light's efficiency (getting the most light out per battery power) since the efficiency is primarily a function of the driver circuit in conjunction with the LED (which is a given). So the art to efficiency lies in the circuit design.
EagleTac D25A mini - XP-G, S2
Olight T25T - XP-G, R5
Olight i2 - XP-G, R5
Fenix LD15 - XP-G R4
Romisen RC-G2 - XP-G R4
On high, the Fenix LD15 was the most efficient with the Olights and D25A coming in within 10% of the LD15. The Romisen came in about 70% as efficient as the LD15. Of note is boost mode of the D25A when first turned on which is 20% higher for 90 seconds.
As far as medium mode goes, the EagleTac D25A has an excellent, efficient run time graph and its efficiency even better than on high which is what you expect. However the Olight i2 was disappointing to see that it's efficiency dropped quite a bit at medium compared to high.
Of note is the fact that the Olight T15 high and medium are about the same level. The reason for this is that the T15 head is the same as the T10 head and the low-med-high spacing was done with the 3v CR123A battery in mind. Thus the AA battery can't deliver the output on high and so it almost directly overlaps the medium mode. With the Olight T15 you basically have a 2 mode light. Thus I also have the T10 tube.
Final comments:
There is a little fuzz on the graph of some of the lights and though the eyes cannot see it, the meter does pick it up. I was sampling at once every 4 seconds. The D25A had a rock solid output until the battery finally ran out of juice. I was rather impressed with the D25A. I liked the spacing of the modes and its efficiency. I also like the Olight i2 because of its mode spacing and because the head is easy to twist to change modes along with it's good beam pattern. But was very disappointed in the efficiency at the lower level. My only complaints with the Fenix is the fact that it starts out on high rather than low and the fact that it doesn't have a medium mode. Also I wish that it twisted a little easier when changing modes. But I do like its size, look, beam pattern, and efficiency. I did like all the beam patterns of all these lights.
The Romisen RC-G2 had a nice neutral tint and beam pattern, but the efficiency wasn't as good as the rest. It resides as my kitchen utility light because its an inexpensive light that basically does the job. In fact, the Olight i2 on medium mode had about the same efficiency as the RC-G2............which was about 56% as good as the EagleTac on medium.
I place a lot of emphasis on a light's efficiency (getting the most light out per battery power) since the efficiency is primarily a function of the driver circuit in conjunction with the LED (which is a given). So the art to efficiency lies in the circuit design.
