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I recently purchased a Surefire torch and proceeded to drain the Surefire labelled CR123A batteries that came with it. I bought some replacement batteries made by Fuji. However, I think the torch is not as powerful as it was with the original batteries. Now I state that "I think" because I've either got used to how bright the torch is or, it's not implausible that I'm just going mad.
My question is, is there any variation between power outputs of 123A lithium batteries?
There can be an extremely small variation in standard lithium batteries, a percentage of a volt, nothing that would be noticable.
Most high end LED torches have regulator circuits in them to keep the voltage steady as the batteries drain so you won't notice a drop in voltage or output until the batteries are near the end of their life.
You might have a dud battery. Try testing them with a voltmeter (you can get a cheap one from www.maplin.co.uk if you don't have one). The voltage of a new 3V lithium battery should be a little over the nominal voltage, probably around 3.2v.
Yeah, I tried a few battery combinations. I think that I'm getting used to and, therefore less dazzled by how bright the torch is, as originally as was absolutely blown away compared to anything I have ever used before and, secondly the environment I was in when I changed the battery (big field) compared to when I first used the torch (indoors). I just wanted to check that I hadn't bought the wrong 'grade' battery or something.
Doesn't take long to get used to, does it? :D All the Surefire L series lights are regulated, so poorer batteries will be just as bright, just less runtime. ;)
Good things, these torches! :D
Ready for the boring scientific bit???
The reason your torch seems less bright is because it probably is!!
At work we use red LED light systems with cameras and a known problem we have is the camera systems needing constant adjustment over the first couple of months.
After a lot of digging the explanation was that when an LED is new it has a nice clear plastic lens, but as it is used the lens is affected by UV light altering the plastic over the first 1000 hours or so until it stabilizes :eek:
I would think with blue / white LEDs the UV level will be higher and the effect will be quicker deteriation, but should stabilize quicker :rolleyes:
Anyone still awake ?? :p
Are you sure that this applies to luxeon LEDs as well, they are not encased in a big dome of plastic?
Sorry for the slow reply - I missed this post!
The LED itself (I believe all LEDS, regardless of size / shape) consists of a semiconductor chip, which creates the light, housed in a plastic case to allow the light to get out. This is the plastic I was referring to, although I guess torches with a plastic lens in front of the LED (eg Petzl head torches) would suffer more degradation from this also.