i think i might do it some day, to find out for real how long they will last, before the light output become useless, as in not even good enough to be a blinker :p

personally i've been recharging the batteries as soon as the HIGH output drops to the Medium output.

it recharges very fast, when i do that.

I remember the first time i charged those batteries it took like 8 hrs

i got the same MTE 8 mode, also using the Trustfire protected ones

My 2-mode Aurora's came in yesterday, so I was able to ride to work this morning again.

I discovered that along one stretch of road, no streetlights, no moonlight, no cars, my Fenix L2D Q5 on the handlebar would not cut it above 20 mph. Determining where the shoulder ends and where the dirt begins is a guess with the light on turbo.

I am extremely happy with 2 P7s on the handlebars. Both on low mode is plenty where there are streetlights. And when I put them both in high, holy crap I can see now!

I don't like these lights with twofish lockblocks. They jiggle when riding and I am nervous about the straps coming undone. I think I will glue together a couple of conduits instead.

I had a car give me their High lights last night. Must be working how they should

Unfortunately my P7 has stopped functioning. I've been in touch with Deal Extreme and they want me to ship it back. I need a working flashlight now, and I can't wait weeks to ship it back and have another one sent to me. I've been told the clicky switch is at fault. Can you purchase these locally? Or even a cheaper flashlight with the same thread/size clicky switch??? I love this flashlight.. when it works, but it's been nothing but trouble since I got the darn thing. Did I mention memory didn't work when the flashlight was functional? :( .......

Have you tried cleaning the contacts on the switch? I've also heard that tightening the lock ring on the switch might help. Use a small pair of scissors or needle nose pliers to do so.

I got this from shinning light, they are in NYC and shipped fast.
there is a coupon code somewhere that saves you 5%.
I'm happy, though I think I liked my Fenix more, time will tell. Then again its about a 1/3 of the cost, I run it with AA, but it will take 1 CR123A.
Its lite so you can always pop it on your helmet.
Then send it back to deal extreme when you get a chance.

http://www.bikeforums.net/showthread.php?t=489032

good luck

Rob

My P7 arrived with a jammed clicky switch. DX quality control SUCKS. They want me to send it back first. Goddamn, what an inconvenience.
Well I managed to use to screws to twist open the lockring in the switch unit. That allowed me to unjam the switch. I think the ring was on too tight. Now it seems to work fine.

I ordered the 8-mode P7-C and also the TR-801 5-mode. The 5-mode came first--rated around 200 lumens, and worked great on a night ride as my only light mounted to my helmet.

Finally the P7 light arrived and I was terribly unimpressed. On medium--the first mode, it doesn't hold a candle to the TR-801--I expected it to be about the same amount of light. On high, it is about as bright or just a hair brighter than the 801.

I've read a lot of complaints about quality problems with DX. Have I run into one, or was did I just build this light up in my head to be more than it is? I know its not gonna pump out 900 lumens like the description says, but I'd think it should blow away the TR-801.

The switch works fine...everything seems to be tight and clean--I'm just not getting the amount of light I was expecting.

Exactly which P7 do you have? The thing with these lights is that there are several configurations of the light driver which pull different amounts of current. Meaning that I light that pulls 2.8A will be brighter but have a shorter runtime (about 40 minutes on a 2200mAh battery) than one that pulls 1.8A (about an hour runtime), and so on.

So the question is, how long is your runtime until the light starts to really dim on a fully charged battery? What size is the battery?

I think you have a dud. Or maybe a crappy battery. Never tried a TR-801, but it sounds very similar to a Fenix L2D Q5, which I do have.
My P7 (http://www.dealextreme.com/details.dx/sku.15691) blows away my Fenix.
Now that I look I see the TR-801 uses an 18650, unlike the Fenix using two AAs, so it's not an equal comparison. Well, similar.

If this is the light you have http://www.dealextreme.com/details.dx/sku.13060 check out the post at the bottom called 'Low Current'

Thanks for the fast response guys. I have the light that Ziemas linked. The "low current" post didn't really make sense to me...does it mean he ordered a part for it and that fixed the problem?

Both of my lights use the 18650, and I think I've ruled out the battery as the problem, since the same battery will drive the 801 just fine but when I move it to the P7 I get blah.

I'll check the runtime probably tonight. I might be able to scratch up a multimeter from my garage, but it's been 20 years since I saw it...

According to the post I linked to the problem seem to be that the light isn't pulling enough juice from the battery to run the LED on full power, meaning that it isn't as bright as it could be.

What's the runtime of the light on high?

I'm regularly getting over 1 hour of runtime on high with protected Trustfire batteries.
As for brightness, this thing is easily brighter than my Trailtech 13W HID lamp. If the HID is 450 lumens, the P7 is 600 at least. The P7 is also several times brighter than my Fenix L2D.
With both the P7 and the HID on the other night, lots of cars were flashing their brights at me. That was pretty much overkill on most well lit streets.

Exactly which light do you have?

This one:
https://www.dealextreme.com/details.dx/sku.12623
Just two modes. Low is pretty darn low.
I wish the beam were less floody. Could use more throw.

There seems to be a lot a variation in these lights, even between ones of the same model. It makes me think that the specs are useless and the factories are just throwing the lights together willy-nilly with the parts on hand.

I ordered this one http://www.dealextreme.com/details.dx/sku.16500 and it's clearly not regulated as the specs say.

Yeah I agree. I did get the regulated batteries though.
QC is shoddy for these lights.

The batteries aren't regulated, they are protected. Regulated means that the light output is more or less constant throughout the charge of a battery. Protected means that the battery itself shuts down if it's over charged or under discharged.

Does any company out there sell a high-quality-controlled P7 flashlight? I'd love to give it a try, but I would prefer to deal with a company with high QC even if it costs double the amount for the light.

OK, I got some information...

I tested the runtime of my P7 tonight, and sometime between an hour and about an hour and 20 minutes the light became noticably dimmer on high, which seems to be about what most people are getting. I started the test inside, but the light was getting very hot--uncomfortably hot in my hand, so I moved the test outdoors.

I also took some pictures of the lights against my shed. Here's a link to the shots. Be sure to click "Detail" to see the descriptions.

I guess based on the pictures that I was just expecting too much from this light.

Remember, a light with 2x as many lumens as another light will not appear 2x as bright as another light; to perceive 2x the intensity, you need 4x the lumen output.

This is part of why I haven't bought a second P7; I know the two wouldn't appear twice as bright as a single light. Another reason is because I don't really feel I need a second; yet another reason is because I'm waiting for one light that would be bright enough to sit on the handlebar and relegate the P7 to being a backup light stored in my backpack.

By the way, I'm not sure how long the logarithmic translation holds up; I've been doing some reading online, and haven't found satisfactory information. It isn't as simple as 2x to 4x, but that's a start.

This article deals with hydroponics, and includes a discussion on growing lights (very powerful ones; 120,000 lumens). Here's a particularly interesting part:

So think about that: on a clear summer day, you might be taking in 10,000 lumens/sq.ft. But it certainly wouldn't appear to be 10 times brighter than a 1000-lumen light at night. And it would be pretty hard to compare the brightness of standing under a tree in the daytime to a bike light in the dead of night, even if both are theoretically putting out the same amount of light. I'd wager the bike light at night would "feel" much brighter, but that would entirely be due to the contrast of the light to the darkness around it.

Our eyes adjust things over a wide scale. The end result is that you can't add the lumens of one light to another on paper and expect them to sum visually; it's not linear.

I'm off to bed soon, but there's loads of interesting material out there on this, apparently.

Not yet, that I know of. There is an MC-E Dreelight, but it's huge and wouldn't be good for cycling. I'm waiting for one too.

Wow! Medium is total rubbish on your light! On my MC-E light medium is between 'Turbo' and 'High' on my Fenix LD2. Yours seems uselessly low....

A lot of people have hyped these lights on here who seem to have little experience with bicycle lighting. There is still a ways to go until we have an excellent flashlight for cycling, but things are getting better by the year.