DP-LED 722b

Just go fishing and try it out.
Maybe it works fine for you, maybe not.

I tried for fishing … but could not see clearly in water where even it was little deeper or waves forming… so I came to the conclusion it requires a higher Lumens Power…thats why I want to know and calculation lumens and Watts of the total flash light…

You’re simply not gonna get what you want from these lights. Now I don’t see a solution here if you still want to buy them. You get another DP 5W light (as opposed to 3W currently) and so what? Get another 60% lumens on top of 50lumens = 80lumens? That still won’t help.

Best case scenario, let’s say their claim of 100lumens is true. Then so what? That’s not enough according to you. Add 60% to that => 160lumens, still not gonna help.

You will want lumens in the count of 1000lm when spotting - definitely not gonna get it from these lights. Unless you’re willing to wear a couple dozens of them all at once.

You will also want warm colour for night fishing, it doesn’t bounce on wave so much and blinds you. These lights? They’re like 8000k, very very cold white. Now, you’d want 3500k or close to that region, you’re not gonna get them from generic LEDs.

Seriously though - you need CREE XML at least, in warm tint. My advice to you - try to get someone with a CC or debit card to help you order online. If you can do that, maybe we can help you with your ordering choices.

Does DP have that Cree LEDs flash Lights…

These headlights are very common at the markets in Vietnam and they go for around $4. Regardless of the amount of leds they generally put out an underwhelming amount of light, probably less than 80 lumens but will do the job if you’re working on something up close. They’re just very cheap plastic headlights and there really isn’t anything spectacular about them.The head straps are also very flimsy break easily.

Yesterday, I sat and did some measurements for the FLASHLIGHT… I calculated out the VOLTS and Resistance for Each Mode ( 1 & 2)

Can you guys now have a look and tell me what would be Its WATTS, LUMENS and AMPERES EXACTLY….

The areas of the Battery Side along with the Circuit photo is attached along as well; to get a more clearer image of the Volts in the Battery produced.

Have a look at the readings and the PICS Below:




Your total is about 0.9W at emitter.

At 60lm/W for these emitters, you get 54 lumens.


There you go. Hope you are finally satisfied. :)

How you came to the 0.9Watts Value for EMitter…?

I have been eagerly waiting for the ultimate answer to the output question for this epic flashlight, and now finally the answer came: 54!

Thank you all for the collaborate effort resulting in the ultimate answer.

(and now go and get a real headlamp )

Cough, cough, ahem

Are you guys gettint annoyed with what I have asked… It is just that inam concluding an answer for it and waiting fo some solid solution and answers to it

I did some more Calculations from the Measurements I did Earlier to calculate the watts and Amperes more Precisely…Can this now help more in calculation of total lumens for light…

1) Now, after so many results and Measurements can we get to a closer value of the LUMENS for the Flash Light …

2) Secondly they claim that it is a 1 Watts Flash Light but through Calculations we found out that; it is 1.1482 Watts … Slightly higher … either we are or wrong, or they are…

3) Why this Formula Mentioned here is not efficient or not suitable for calculation of Lumens for this White Straw Hat LED Flashlight… or is it suitable…If, not then for what purpose is it used…?

guys, any hopes with the new data and list mentioned in the top post…

I wish I could contribute to this thread other than to say that the patience, tolerance, and understanding by members of this forum is inspiring.

Again, with your “new” calculation:

Average LED Vf: 3.1625V
Total LED If: 0.28637A
Power = 0.905W

And thus:

Farhaj,

As others have stated, you can perform all the calculations you want, but without taking actual optical measurements using an integrating sphere and a lab calibrated luxmeter it’s IMPOSSIBLE to get anything more accurate than an estimate of the lumens of your light. You might get what’s hopefully a close estimate… but it will always remain just an estimate.

You seem wedded to the belief that you can get an absolutely precise value for the lumens from your light simply by measuring electrical properties and relying on manufacturer specs…. without doing optical testing. You’ve chosen your approach and are fixated on it. You’re rejecting the advice of everyone who tells you that what you want to do can’t be done.

It is of course your choice to believe whatever you want, but it might be wiser to ask yourself if your approach is actually the right one.

1. I can buy this headlamp with $4 in my country everywhere… but with $31?? What??
2. This headlamp is cheap for a reason. It is only meant for general use.
3. I am amazed by the patience of our fellow BLF members.
4. We don’t know what you actually want so I am giving you equations, perhaps you can calculate them in your own.
V = IR
P = VI

Or the easier way .

And hopefully you don’t take the “DP” brand as gospel. Do more research and you will find out there are actually a lot more better flashlight brands ranging from budget to premium. To give you an idea these are all the better headlamps .

a neighbor bought one of these at a local flea market for $2.
its too heavy thanks to the lead acid battery.have to really tighten the headband and its uncomfortable and frontheavy.leds are blueish.
but he wants to hotrod it.dont know if 18650 will fit yet.
cheap charger.a bridge and capacitor current limiting.
everything about it is cheap.told him to exercise the pivot and band a bunch to see if its going to fall apart first.
a laptop pull and usb board would triple runtime and remove 2/3 of the weight.
and the hi cri leds i have would greatly improve light quality and quantity.

as for all the pointless calculations about output the only correct answer is to stick it in an integrating sphere and measure it!
i will simply assume it was built with toy grade leds and will not uphold any CLAIMS made on the box or led datasheet.the CLAIMS were likely pulled out of someones backside.

Hehe,. I just gave this thread a read and i must say that I am also amazed at the patience and tolerance of some of the members here! I would have ducked out long beforehand! Honestly, he could exchange for an 18650, or for the price of an 18650 he could go buy a Thorfire headlamp that outputs every bit of 300+ lumens using 3x AAA’s.