About runtime and efficiency

I was comparing Armytek Wizard Pro and Spark SD6

And i came to the following chart:
Spark SD6:
Super: 460lm/1.8hours
Max: 200lm/3.5hours
Med2: 70lm/12hours
Med1: 12lm/120hours
Low: 0.5lm/90days

Firefly 1 = 0.5 lm = 3050 hours or 127 days
Firefly 2 = 7 lm = 217 hours or 9 days
Mode 1 = 30 lm = 37h 29m CONFIRMED2
Mode 2 = 115 lm = 14 hours
Mode 3 = 250 lm = 7h 23m CONFIRMED1, 7h 59m CONFIRMED2
Mode 4 = 550 lm = 2h 59m CONFIRMED1, 3h 12m CONFIRMED2
Turbo = 1010 lm = 1h 08m CONFIRMED1
which comes from review on this forum

The Wizzard Pro has a much lower runtime than the SD6
Is the output of Wizzard Pro lower than what it states? Or?

How can a headlamp has twice efficiency than another one?

Spark runtimes are for 2400mAh and for Cree XM-L T6 led.
Armytek Wizard Pro runtimes for 3100mAh and for Cree XM-L2 U2 led.

XM-L2 have lower forward voltage, so it's easier for 1x18650 application.
XM-L T6 vs XM-L2 U2 means about 25% more light at the same power.
2400mAh vs 3100mAh means 29% more energy in the same size cell.

Then you have to add PWM ratio to this equation, Spark is current controlled instead of using PWM for their modes, and according to the testers Wizard is PWM heavy in lower modes. It means that the lamp does not emit light for some amount of time -> the burn time will be longer.

Then you can compare both runtimes, we have over 100* down here today so it's all from me :tinfoil:

- Agree with different battery capacities
- Most of Selfbuilt's tests show emitter upgrades to yield significantly less than what CREE and the light manufacturers market as "up to xx% brighter"
- I understood current control is more efficient than PWM
- I test my light's output with a light meter, and randomly with a stopwatch, and find that while there's certainly differences in driver efficiency, the biggest are driven from marketing conservatism/exaggeration.

Unfortunately, comparing different lights on "ANSI specs" is kind of a joke (IMHO). Selfbuilt's test are a good common/consistent standard by which you can derive at least a manufacturer's common level of conservatism/exaggeration, if not the actual lights in question.

EDIT: One of SBs reviews believes Armytek to be using emitter lumens, not OTF, which would account for 25-30%

I have both the Armytek and the Spark headlamps, I love both of them (for different reasons) but I can tell you definitely that the Armytek is a lot more efficient (this is based on actual testing and not reported marketing hype from the companies) in the higher lumens. The LEDs that companies use, even if they are the same can vary greatly from one bin to the next couple that with an even greater factor, the driver and you can have great differences in efficiency. Driver efficiency can vary greatly from manufacturers and that is what usually separates one manufacturer from another. Some manufacturers will design their own proprietary drivers others will use drivers that are mass-produced. Even the components used for wiring and spring material can play a difference in efficiency. Just my $.02 on the subject.

Knight_Light said:

Even the components used for wiring and spring material can play a difference in efficiency. Just my $.02 on the subject.

Click to expand...

Even adding magnets (like you are suggesting CPFers to buy after the Armytek Wizard Pro's cutoff problems) would play a role in that as well by changing the resistance, wouldn't you say? I cannot see how that would help increase runtime at all. What say you?

Beacon of Light said:

Even adding magnets (like you are suggesting CPFers to buy after the Armytek Wizard Pro's cutoff problems) would play a role in that as well by changing the resistance, wouldn't you say? I cannot see how that would help increase runtime at all. What say you?

Click to expand...

The magnets will definitely affect the efficiency of the headlamp how much would have to be actually tested. A lot of it would also depend on the type of magnets used. But I don't think you have much to worry about since you run everything in sub lumen mode.

I would still be concerned, since one of the main reason I am running things in sub lumen mode is to maximize the amount of runtime out of any of my lights.

Hey, BOL. One of the main reasons I was considering the current Armytek offerings is their claimed wickedly long runtimes in firefly and their long range throws on high with a fresh battery.I'm a sub-lumen fan, but I love versatility!

Knight_Light said:

The magnets will definitely affect the efficiency of the headlamp how much would have to be actually tested. A lot of it would also depend on the type of magnets used. But I don't think you have much to worry about since you run everything in sub lumen mode.

Click to expand...

What magnets, how and where?

nuambenzina said:

What magnets, how and where?

Click to expand...

Inside the battery tube between the battery and the spring.

The nickel coating on the magnet is not as conductive as the battery is.