As many of you know, I have been testing the Twin E2 to learn more about crud buildup when the coils are operated at a lower voltage.
http://www.e-cigarette-forum.com/fo...iew-tips-info-help-video-226.html#post2149424
http://www.e-cigarette-forum.com/fo...iew-tips-info-help-video-288.html#post2175504
To jog your memory, this one has two E2 3Ω coil and wick assemblies. The coils are connected in series, making them the equivalent of a 6Ω coil. What this all boils down to is that each coil works at 1/2 the applied voltage. In other words, a 5 volt source operates each coil at 2.5 volts. At this voltage, however, the dual wicks give off a bit more vapor than a good working E2 at 3.7 volts. I can get by with less than this and have operated this mod down to 4.2 volts, or 2.1 volts on each coil.
Therefore, the testing for crud buildup was performed within the voltage range of 4.2 to 5 volts, or 2.1 to 2.5 volts on each coil. All testing was done with my juice. Another kind may have yielded different results.
Nothing great has been learned about crud buildup from these tests. Common sense told me ahead of time that the buildup rate should be slower at these lower voltages, and that was confirmed. I ran an awful amount of juice through this thing. The last test was run until the crud was bad enough to noticeably reduce the performance. This required several days of vaping myself silly. So, about all this test amounted to is that if you can get by with operating your E2 at a lower voltage, then you can go a bit longer before rejuvenating the coil. I'll also say that the coil may have a longer life with less voltage.
Now it would seem that this test was a waste of time. That is not the case. One wick is free standing and it picks up a bit better than the one in the slots. The coil runs a bit cooler for this reason and the crud buildup is slower than the other. This is not all that noticeable by looking at it during use, but it shows up right away during a dry burn. It burns completely clean while the other one is still struggling to burn enough black off to see a glow. I suspect there may be more involved here than just this observation, but that's yet to be determined.
Before you begin thinking that we need a free standing wick and coil, there's more you should know. This wick is not controlled and it does too much. While standing upright, it drips a small amount while not in use. For that matter, the one in the slots does too much. Just not as much. As a matter of fact, if this mod is left standing upright overnight, the tank will be empty the next morning. Now, the free standing wick is above the cup, so it does not reach down to the bottom of the tank. Only the one in the slots can drip enough to completely drain the tank.
I don't know what I'll do with this thing now. I'll have to admit that I like it. As a matter of fact, I like it too much. It's too easy to keep getting more out of it, and instant gratification is getting the best of me. I find myself pulling longer on my other ones now to make up the difference. I was afraid this would happen.