I received a shiny new SS El Capitan in the Christmas giveaway this year, and wanted to post my impressions so others might benefit. As the title of this thread suggests, my focus will be about how QTC functions in an older, non-QTC El Capitan.
Here is a list of things I like about this light. This thing is built like a tank. It's the most durable (and probably the most reliable) light I own. I like that you can unscrew the keychain if you want the light to tail stand, and I like that you can adjust how deeply the battery sits in the battery tube by adjusting the brass screw behind the keychain attachment. The beam is nice and floody, which I prefer.
Things I don't like: I would like to see a much more agressive knurling. It's also heavier than I like, but I understand that this comes hand-in-hand with the durable, steel body.
Now to the QTC part of this review. Information about the Peak flashlights can be hard to come by, and here are some of the things I would have liked to know in advance. To reiterate what I said above, the El Capitan that I have is a non-QTC version.
The brass screw behind the keychain attachment makes it easy to accommodate the QTC. If you back the screw out, there's a little extra room in the battery compartment. Depending on how much extra room you want to create, you may have to grind down the brass screw a little bit. I plan on doing that this weekend. I hope to take about a millimeter off the brass screw where it usually makes contact with the battery.
As far as HOW to place the QTC, you have a few options. First, you can try to carefully place the QTC down inside the foam ring, so that it is sandwiched between the battery and the brass screw. This isn't a bad solution, but I don't think it's very optimal. The QTC doesn't stay put and you have to be careful when placing the battery or you'll damage the QTC. The solution I like better is to use a small magnet to attach the QTC to the negative terminal of the battery. I have some neodymium magnets that are about 5mm by 0.5mm, and they seem just about ideal for this purpose. Simply center the magnet on the negative battery contact, and then center the QTC on the magnet. The magnet is strong enough that neither it nor the QTC will slide around once it is affixed. Drop in the battery and go.
The downside to this solution is that you need to shorten the brass screw a little to make it all fit. You can back the brass screw out enough to work, but it doesn't leave you enough space to screw the keychain attachment back in. I'll post an update after I grind down my brass screw this weekend.
Another thing I wanted to mention was brightness and runtimes on low with the QTC. It can be pretty hard to adjust the light to a very, very low setting (especially with a full battery). Additionally, even after you get the output where you like it, it never stays there. In my case, I wanted the light barely on, so the LED die is just barely glowing. You can get it to that state, but if you let it sit at that brightness overnight, you'll wake up to find that it's producing a solid 3 lumens in the morning. So you turn it down again, until the die is barely glowing, but several hours later it has ramped up again. Sometimes, if you turn the light completely off, but with the head screwed in to the point where it's close to activating, you'll come back to find your light has turned itself on.
With all of that in mind, my light has been running non-stop for 9 days, and it's still going. I adjust the brightness down to where it's barely glowing maybe 4 times per day. After I wake up, sometime before I go to work, after I get back from work, and before I go to bed. If I were to guess, I'd say that over the last nine days, it has averaged about 1 lumen output. Keep in mind that It's hard for me to judge actual lumen output ratings. The only light I have that I can compare it with is a D10 R2, which is supposed to run about 3 lumens on low. I'll keep everyone updated about the final runtime.
Overall, I'm extremely impressed with this light. The QTC is a little finicky, but I think that's worth the extra reliability you get out it. I doubt this will be my first Peak.
Just an update. It's been 15 days since I turned the light on, and it's still going. When I turn it up to max brightness, it seems just about as bright as it did when I first put the battery in. It's probably not actually that bright, but I have no means to compare. Still, it's darn bright.
I don't need to lower the brightness as much as I used to in order to compensate for the QTC letting more current through. Maybe once a day I lower it. I've noticed now that if I go too low, the QTC will adjust the brightness DOWN until the light is turned off. I'm trying to keep the brightness around 1 lumen, as judged by the 3 lumen setting on my D10. Completely unscientific, but there you go.
Thanks for taking the time to do this test SG, with QTC these are very important because it gives us a rough estimate of what to expect out of a particular model, since we cant measure or regulate with precision the output, other users experiences become a lot more important even if the range of output/runtime is too wide it still gives us something to go by.
I'm happy to do it. I wished there was more information out there about this stuff when I was shopping for a light, so maybe this will help someone.
Day 16, still going strong.
Maybe someone can answer this question for me. Is it possible/expensive to convert my non-QTC light into the QTC version? Are the bodies the same? From the pictures I've seen, it looks like I may just need to replace the brass screw behind the keychain attachment.
not fully compatible, the inside space in the bodies is larger in the QTC models to acommodate the QTC pill that holds the QTC material, iirc the threads in the head of most models also have more lenght on the QTC models, they are the same diameter though, so you could maybe use the head on your El Capitan with a QTC body and compensate the lenght somehow (like adding something in the positive brass contact).
It's day 25 of my test, and I'm completely bewildered by the fact that this light is still going! Honestly, I thought I'd be lucky to get a week out of this test. I must have it set at a much lower level than I first thought. But it doen't seem like a low level. I like it dark when I sleep, and the dumb thing keeps me up at night sometimes. With night adjusted eyes it nearly lights up my whole bedroom. Easly enough to navigate around the house by night, and a little brighter than I'd like to be honest.
Am I the first person to do this test? The only thing I can think of is that myabe my prankster roommate is sneaking in here to change the batteries every once in a while.
Excellent job, and quite a bit of patience. It's been about one month since your last update. How long did it last? Just received my SS El Capitan today, pocket carry. Though twisting through levels isn't the smoothest, still very impressed with this light. Edit: After using for about an hour, I think when switching to higher modes, and then turning to lower modes, the foam ring will further decompress and apply more pressure to the battery which will cause the lumen output to increase somewhat.
I was absolutely certain I updated this thread with the final runtime. I remember writing it! But it's not here, so thanks for reminding me to update, LGT.
I stopped the runtime test after 31 days. It was still putting out a useful amount of light, but I estimate that it was only about one lumen on high, as compared to my D10. I even took out the QTC to see if it would put out more light, but it didn't. I'm sure I could have gone for a few more days with diminishing output, but I was happy calling it at a month.
Also, I wanted to mention that I took about a millimeter off the brass screw behind the keychain attachment to make room for the QTC, and it works just fine. Now the keychain attachment screws all the way in, and it didn't before.