What's wrong with my Ultra-G?

What\'s wrong with my Ultra-G?

I recently got a CMG Infinity Ultra-G, and decided to perform a very unscientific run test comparing it to my 2 other Ultras, and one standard Infinity. I guess this test was partially a test of different battery types as well. In the Ultra-G I put a lithium AA, in one of the Ultras, I put an Everactive (Walmart) alkaline AA, and in the other Ultra, I put a Ray-O-Vac heavy duty zinc chloride (not alkaline) battery. In the standard Infinity, I put an Everactive alkaline AA. Well after about 14-15 hours, my Ultra-G was dead, after I fully expected it to totally smoke the other 3 lights. I thought maybe I had a bum lithium cell, so I installed a new lithium cell and continued to time it. Same result. I then tried 2 different alkaline cells in the Ultra-G with the same results, while in the meantime all the others kept shining brightly. It has been just over 51 hours now, and the other 3 lights are still going, with the standard Infinity leading the Ultras (they are both very dim now, but still going.

Anyway I happened to be in the room while the Ultra-G went dead on time. It was bright, and the turned off like I had shut it off (it didn't slowly dim or anything, it just shut off). After playing with it for a while, I discovered that if I give it a minute in the off position, I could turn it back on, and it would glow brightly, but only for a minute, sometimes less. Sometimes if I were to whack it against the table, it would light up, but only to go dark again. Sometimes when it would go out, it would blink on then off, then on, then off. It would do this several times.

Does anyone have any ideas what might be going on here? I tried cleaning the threads with a tiny wire wheel on a dremel in case there was anodizing on the threads creating resistance. Could it be that I simply got one that requres too much current?

Any help would be much appreciated. Thanks.

Re: What\'s wrong with my Ultra-G?

How does the brightness compair to the other lights. You may have a brighter led in the "G" which would lessen the runtime as compaired to the other lights.

Re: What\'s wrong with my Ultra-G?

Yeah... I haven't done any runtimes, but of the three Infinity Ultras I own, one is a tad brighter than the other two so I would expect lesser runtime.

Re: What\'s wrong with my Ultra-G?

The G is just *slightly* brighter than the Ultras, but it's almost indetectable. The odd thing is the fact that when I let it sit and turn it back on, it's just as brightas it was when it shut off. And it had not dimmed all that much by that point. It was about the same brightness (maybe a hair more) as the Ultras when it went out.

Re: What\'s wrong with my Ultra-G?

[ QUOTE ]
_mike_ said:
They do seem to last a very long time on one battery.

However, seems to me I remember milkyspit telling how using lithiums in the Ultra Infinity would not get as long a run time as opposed to using plain old alkalines.


Ahhh, here it is.....
[ QUOTE ]
milkyspit said:
Guys, here's what's happening with the Ultra. It's not regulated, but uses only a voltage boost circuit. Doug Owen and others have studied the circuit's characteristics fairly extensively, and it's clear that there's no regulation going on in there, even though the marketers call this a "regulated" light.

Now don't flame me, please, because I love the Ultra! It's my favorite of the single cell Nichia lights, and a great value IMHO. But I also believe in calling a spade a spade, and in this case, the Ultra is simply not regulated.

With that in mind, it's easier to understand the "strange" behavior using a lithium AA cell. The way the circuit works, the higher the input voltage, the higher the output current flow to the LED. A lithium AA cell has a higher voltage than an alkaline cell, plus doesn't experience as much voltage sag under load. The bottom line is that it delivers more voltage to the circuit, and hence more current flow. So far so good. But two things happen...

1. Even with an alkaline, the LED is driven beyond spec. The additional current flow from the lithium doesn't result in all that much more light, mostly just increased heat. To be sure, you can see the brighter lighting on a lithium AA cell in a side-by-side test of two Ultras, but just eyeballing a single light first with an alkaline, then with a lithium, you would have a hard time seeing it. And the heat wouldn't be that noticeable because it's not all that much heat to begin with. Certainly nowhere near the heat generation of a typical Luxeon. So to sum up this point, there is more light, but you probably wouldn't notice.

2. The increased current flow will cause the lithium cell to deplete itself more quickly than the alkaline. A fresh lithium AA cell has 3000mAh stored energy, while a fresh alkaline has 2850mAh. Pretty close. The small advantage with the lithium will be more than negated by the light's faster consumption of that energy due to the higher current flow. That's why the lithium cell is measured as having a marginally shorter lifespan in this light than does the alkaline.

Incidentally, the reason a lithium does so well in those other lights has more to do with the alkaline being "miscast" in those lights (to use theater terminology) in the first place. Alkalines excel at delivering small amounts of current flow. They're rated for current flow of 25mA. A typical incandescent light and even a Luxeon light, though, will demand 500mA or more. At that level of discharge the alkaline will no longer exhibit its rated capacity of 2850mAh, but instead will behave as if it has far less capacity. Meanwhile, the lithium cell will crank out these higher currents with much less degradation of its capacity rating. So the higher the current draw, the greater the benefit to using lithium cells.

Hope this helps. /ubbthreads/images/graemlins/smile.gif

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Read the entire thread .... here.

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Re: What\'s wrong with my Ultra-G?

Also, if you use your lights in a more normal manner you will probably get more hours out of them. If you do let them run continously for hours at a time, shutting them off for awhile even for 24 hours will get you some additional run time. That's more a characteristic of the battery not necessarily of the light, in this case an Ultra-G.

Would be my guess that there is nothing wrong with your light.

Re: What\'s wrong with my Ultra-G?

No, there's something wrong with it. It happened with an alkaline cell too. It's bright, then all by itself, it shuts off, no dimming, just shuts off. In the meantime, all my other Infinity's are still plodding along, even the one with the lowly heavy duty battery. It should have lasted more than 14-15 hours. It appeared to be very bright still when it went on the fritz, no matter the battery type. It should have slowly started dimming, and lasted at least 25 hours, after all, the others are still going after over 50 hours!

Re: What\'s wrong with my Ultra-G?

Here's what the runtime plot on my Ultra-G looks like with a alkaline battery.

Re: What\'s wrong with my Ultra-G?

Well it happened again. This afternoon I replaced the battery with a brand new one, and it went dead in less than 6 hours. It would flicker when I whack it against the table, or try to turn it off then on. Meanwhile, the other ones are still burning. I wonder if CountComm will exchange it for me.

Re: What\'s wrong with my Ultra-G?

Big_Ed,

The folks at CountyComm do a really nice job of taking care of their customers. Better shoot them an e-mail soon however and explain your situation. They apparently are quickly running out of the Ultra-G's and will not be getting anymore.

Re: What\'s wrong with my Ultra-G?

Thanks, I'll do that.