Headlamp run time standard?

[gcbryan]

I emailed Black Diamond to ask how they can come up with a run time spec for the Storm on max (100 lumens) using (4)AAA's of 50 hours.

Of course if you break it down by battery capacity and emitter wH requirements on high you get something in the 4 hour range.

Their answer is that they use an outdoor industry standard used by other manufacturers to allow for fair comparisons between competing products. That standard is to turn the light on (high) and measure the time until the output is down to .25 lux at 2 meters (moonlight equivalent).

Not much of a standard in my opinion. Someone with a true regulated light rather than just the first 25% of battery capacity (Storm) would show 4 hours using the same batteries and emitter as the Storm.

It would be OK as a standard if that standard was mentioned along with the 50 hour figure.

When someone is thinking about buying a headlamp that produces 100 lumens I don't see how telling them it has a run time on max of 50 hours tells them anything at all.

 

[robostudent5000]

good points. i think this further underscores how difficult it is to compare lights by just their specs and points to the value of forums like this where users can share experiences of light performance in actual use, with a note of appreciation in particular for those users who conduct and post lightbox and runtime tests.

 

[gcbryan]

I also just assume that most lights using the same emitter/battery combination are going to have roughly similar run times. There is no magic 🙂

It's the other features that I end up basing my decision on. It would be nice if they didn't seem to imply the impossible regarding run times however 🙂

 

[ahorton]

It is bad advertising but it doesn't surprise me at all. I learnt years ago that no matter what you're looking at, if you don't know the field inside out then you need a friend who can ask the right questions.

Every car add tells you the power of a vehicle but you need to ask what the torque is and at what rpm.
Every real estate agent tells you about the bathroom fittings but you need to ask about the soil it was built on.
Every 21 year old is pretty but you need to find out what her eating/exercise habits are like and meet her mum...

I don't expect headlight manufacturers to be much different, but I do have instant respect for those who give me the right bits of data.

Most shoppers will not ask the right questions in any field but they walk away happy because they know they bought a product that did well in the 'standard' test. They are the lucky ones.

 

[robostudent5000]

Every 21 year old is pretty but you need to find out what her eating/exercise habits are like and meet her mum...

i'll cosign that one. :hahaha:

 

[Lynx_Arc]

I ignore runtimes listed on lights and try to estimate current use and as I almost always use nimh it makes it easy to calculate vs alkalines. Alkaline battery runtime on non regulated lights depends largely upon what output levels are acceptable to the user as to when to change batteries. The typical inflated runtimes dwell deeply into moon mode territories on lights so you basically consider them emergency runtime not normal runtime levels. Let's face it, if you allow a 1 lumen output to be part of runtime on a light using 3AAA batteries the current draw could be a fraction of a milliamp on the latest efficient emitters. I have taken a single 5mm cree direct drive off 2AAA nimh and ran it for over a week putting out light enough to walk around in a pitch dark room. The current draw when I decided to recharge was 0.4ma. At that current rate you only use 10mah in a day so in theory an 800mah nimh could run for 80 days (but won't because that would require a regulated circuit to maintain that level of output at start and prevent output from dropping below that near finish.

 

[carrot]

It's true that the ratings used by headlamp mfrs is imprecise... but so is the terrible ANSI/FL1 standard.

 

[Szemhazai]

Yep, but it's some kind of standard - nothing have changed here till her majesty the halogen bulb - when you get 0,25 lux (it's light at the fool moon) from the 4xAA headlamp working on the halogen bulb it's almost dead but it's just after 5 hour's of work and it’s after rapid drop in last 15 minutes. Using LED bulb the “drop” take days…

 

[Lynx_Arc]

It's true that the ratings used by headlamp mfrs is imprecise... but so is the terrible ANSI/FL1 standard.

I agree, I thought it would be better but why they allowed runtime to include such low light levels when LEDs were involved makes it impossible to trust the numbers. Either you use nimh and the light drops down to dim after the batteries deplete or you end up a third of the way to 100 hours runtime squinting to see as the light is now 10% of what you started with. They should have used a larger number at least 30% of starting level or level after 5 minutes into runtime. I would see having a 40 lumen light at 12 lumens and consider that runtime is reaching the end of usefulness.
I have seen several lights with multiple modes where the low mode was nuts in runtimes. If it was a percentage of starting level then the miniscule number based upon the start could be around 1 lumen or less. That may be useful as an area light but for the most part a headlamp isn't used that way.