Surefire U2....

Freedom1955

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Holy good God Almighty does my U2 like to eat battery's. I'm not sure of the run time but it didn't take long to go through the first set. /ubbthreads/images/graemlins/frown.gif
 

PhantomZ

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runtimes for U2,

level 1 - 1hr
level 2 - 3hr
level 3 - 5hr
level 4 - 10hr
level 5 - 20hr
level 6 - 40hr

it should drop a level or 2 if you were using it on level 1 for a long time. it'll still give you plenty runtime. if you're worried still about using up alot of batteries maybe you would invest in a Pila battery?
 

Freedom1955

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I've been using it on level 1, on and off momentary with the occasional 2 min run. All of a sudden it went from level 6 to level 1 in a matter of seconds and started to blink.
Is this the way it is supposed to happen when the battery's get weak?
 

nobody

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[ QUOTE ]
Freedom1955 said:
Holy good God Almighty does my U2 like to eat battery's. I'm not sure of the run time but it didn't take long to go through the first set. /ubbthreads/images/graemlins/frown.gif

[/ QUOTE ]

I think you need to trade that battery eating POS to me for my Infinity Ultra...:D...The battery in the Ultra seems to last forever...maybe too long. Let me know when you've finally had it with feeding that hungry light.
 

wasBlinded

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You'll feel better if you get a couple of 18650 Li-ion cells from 4Sevens for $9 each, and a decent Li-ion charger. Then you can use your U2 to your heart's content without agonizing over spent CR123 cells.

The 2400 mAh 18650 will give you 2-3 hours runtime on the second highest level, but on the brightest level will be somewhat less than you can get with fresh CR123 cells.
 

KevinL

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[ QUOTE ]
wasBlinded said:
The 2400 mAh 18650 will give you 2-3 hours runtime on the second highest level, but on the brightest level will be somewhat less than you can get with fresh CR123 cells.

[/ QUOTE ]

Actually, somewhat more, surprisingly. The 1800mAH are the ones with less runtime than CR123s, but ever since the upgrade to 2400mAH, wow /ubbthreads/images/graemlins/smile.gif it just keeps tickin'..

The U2 is a little bit of a battery hog at full power when using CR123s, but it wasn't meant to be run at full power all the time, that's why they let you dial it down. I find level 5 is perfect for getting double the runtime for not that much less light.

Update: I just finished a runtime test on my U2 with 4sevens' 2400mAH LG Chem cells. As I do not have a light meter, I relied on a more primitive method - measuring how long till I completely lose level 6, ie. there is no discernable difference when I turn the dial.

I'm referencing kj's runtime charts. His U2 in particular has a regulated level 5 of 1400 lux, which can be correlated to his level 6 graphs, which reach 1400 lux after 55 minutes on Pilas. In other words, he has 55 minutes till his lightmeter cannot tell the difference between level 6 and level 5, which is the defined endpoint of my test.

I managed to get 85 minutes till it reached that point on a cell that was charged to 4.10V before the test began. Probably more if the cell had been charged all the way up to 4.2V, maybe as much as another 5-10 minutes. So yes, these are better than CR123s even /ubbthreads/images/graemlins/smile.gif

The cell measured 3.59V at test termination.
 

cliff

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I use my U2 alot and switch out Pila 168A (2000 mAH) batteries every day or so. Haven't run one dry yet and like I say, the light gets alot of use. Once you absorb the cost of rechargeables, there is no further expense.
 

Freedom1955

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[ QUOTE ]
wasBlinded said:
You'll feel better if you get a couple of 18650 Li-ion cells from 4Sevens for $9 each, and a decent Li-ion charger. Then you can use your U2 to your heart's content without agonizing over spent CR123 cells.

The 2400 mAh 18650 will give you 2-3 hours runtime on the second highest level, but on the brightest level will be somewhat less than you can get with fresh CR123 cells.

[/ QUOTE ]

I ordered some of those r123's and a charger from BatteryStation a couple days ago. I plan on using them in my Q111. I've read here that you should not use those in a U2,is that correct?

If so will the r123 charger from Batterystation work with those 2400mah 18650's?

Thanks
 

wasBlinded

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Don't use two R123s in a U2, it will seriously overdrive the LuxV. Anything over about 7 volts will overdrive it. The 18650 won't fit into an R123 charger, but if its a 'smart' charger it would do the job if you could find a way to attach it to the cell.

Here is a runtime plot of my U2 on one of 4seven's 2400 mAh 18650 cells, charged to 4.20 volts. The maximum lux of this U2 with two fresh CR123 cells is 1945 lux.

U2_18650.jpg
 

KevinL

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wasBlinded: thanks for the excellent graph and for confirming what my primitive testing methods were trying to discover, that the U2 runs for around 90 minutes on the 2400mAH cells before falling out of regulation. /ubbthreads/images/graemlins/happy14.gif

Freedom1955: I would be very careful of using chargers designed for one kind of cell on another kind of cell unless they are known to be universal chargers designed to charge any size and capacity of lithium ion/lithium polymer cells. I am using the Maha C777Plus2 specifically designed for 1-4 cells, both li-ion/li-polymer chemistries, and all sizes of cells >400mAH.
 

Luna

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Kevin it looks like your tests are close to mine.

I have one LG 2400 that I have charged to 4.35 volts using the cheapo lion charger (even with a PCB!!!) so take heed.

I could use the Triton on it but I'm curious as to how many charges I get out of it now. (With the Triton, I set it for the 3.7v cell, not 3.6 and I get a full 4.2 charge)

Right now it is going strong so I wonder if the newer chemistry is more resiliant than the older, but the test is still only in the beginning. After a week of mixed low use it is still over 4.2v. Given the cost, I think it might be a reasonable sacrifice and maybe even std practice.

If I get the chance this weekend I will put a light meter on it vs the primaries. I gain nothing on Cr123as with the low tech metering. The higher voltage on the high cap cell might be why I like the U2 so much with the 18650s.
 

Luna

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PS, my Triton has the latest software (green sticker on bottom) that deals with the Li/ions better than the past versions
 

Codeman

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Dang, I believe I could drop my U2's reading with a Pila 168A on top of your graph and they would come extremely close to being the same. I haven't logged the output, but the starting lux as as well the time when it drops out of regulation rapidly are practically identical!
 

Freedom1955

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[ QUOTE ]
Codeman said:
Dang, I believe I could drop my U2's reading with a Pila 168A on top of your graph and they would come extremely close to being the same. I haven't logged the output, but the starting lux as as well the time when it drops out of regulation rapidly are practically identical!

[/ QUOTE ]

Codeman,
Did you just say that a U2 will run on level 6 for 90 minutes using a Pila 168a /ubbthreads/images/graemlins/confused.gif?
I thought I read that the U2 won't run very long on level 6 with a Pila 168a. /ubbthreads/images/graemlins/confused.gif
 

wasBlinded

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It won't run at full brightness on a 168A or an 18650 for more than a few minutes. For most of the run time on level 6, the brightness will gradually diminish though still remain above level 5 brightness. By the time the light reaches level 5 brightness, the Li-ion cell is pretty much all used up.

You can tell from the graph that for almost the entire run time on the 18650 (and a Pila 168A has almost the same capacity) the light is running at 80% full brightness or better. Thats not much of a sacrifice to make for using a rechargeable, to my mind.

The downside to a Pila 168A compared to the 18650 is cost - Pilas are kind of expensive. The upside is that they don't require a smart charger. The Pila charger is pretty simple and easy to use and not terribly expensive.
 

Freedom1955

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[ QUOTE ]
wasBlinded said:
It won't run at full brightness on a 168A or an 18650 for more than a few minutes. For most of the run time on level 6, the brightness will gradually diminish though still remain above level 5 brightness. By the time the light reaches level 5 brightness, the Li-ion cell is pretty much all used up.

You can tell from the graph that for almost the entire run time on the 18650 (and a Pila 168A has almost the same capacity) the light is running at 80% full brightness or better. Thats not much of a sacrifice to make for using a rechargeable, to my mind.

The downside to a Pila 168A compared to the 18650 is cost - Pilas are kind of expensive. The upside is that they don't require a smart charger. The Pila charger is pretty simple and easy to use and not terribly expensive.


[/ QUOTE ]

Thanks for the explanation.
 

Codeman

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What I meant is that it runs on level 6. I've read that some of the Wolf 168A won't even reach level 6. Both of my Pila 168A's start at around 1875 [email protected] meter and pretty much stay there until right about 90-93 minutes, then brightness drops like a rock. Around 96 minutes, only level 1 is available.

I've consisently gotten these results over several runs with both Pila's I have.

When I use SF123's, it starts around 2310 lux @ 1 meter.

I don't mind the extra cost of the Pila's. It's a good trade for the protection, IMO.
 

JanCPF

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Is U2 level 6 on Li-Ion as bright as or brighter than an L5 in full regulation? How about U2 level 5 compared to L5 brigtness? I've never been able to get an answer to these questions, probably because very few people have got both lights. BTW do we have a lux reading of an L5? Thanks.

Jan
 

Hoghead

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Jan,

Someone with a light meter could better answer your question. I just did a quick comparison between the L5 & U2. The U2 has a Pila 168S in it. The L5 had Surefire 123 primary cells. This is the way my lights looked to my eyes.

The U2 on level 6 is brighter than the L5.

The U2 on level 5 is about the same brightness as the L5.
 
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