The BEST little flashlight in all the world - I'm serious

falco · May 7, 2013, 10:56pm

ToyKeeper:

falco:

Ubehebe:

I have heard from hubbies that a couple gals actually wear the thing around the house and use it rather than switching lights on and off, captured by the thought of saving electricity.

I’ve wondered about this. But for the same amount of light, wouldn’t using a flashlight be less energy efficient since you would lose some electricity charging up the batteries and some more due to the battery just discharging over time? On the plus side, a flashlight is much more directed light so you wouldn’t need to light up a whole room.

(emphasis added)

Depends. I’m not sure what the runtimes on the Tank007 E09 are like, but I’m pretty familiar with my ZL SC52. It gets 2.7lm for ~96 hours per battery, and has other modes when necessary. In practice that’s enough runtime to last me for a whole month of not-using-overhead-lights for a few hours per day (let’s say about 3 hours per day). (I’ve actually done this with my ZL H51w, which is less efficient than the SC52, and one cell lasts about a month)

But how much electricity does it take to charge one 2000mAh Eneloop? As far as I can tell, my La Crosse BC-700 charger spends about 2500mAh at 1.6V, or about 4 watt-hours, to charge one cell. I used its built-in counter though, rather than a kill-a-watt, so I’m not sure if actual usage might be a bit higher.

Compare that to using a light bulb… The Phillips L-prize winner bulb gets 94lm/W or about 910lm from 9.7W, and is the most efficient bulb on the market. At 3 hours per day for 30 days, that’s 9.7W*3h*30d == 873 watt-hours, or about 218 times more electricity than the flashlight approach. But maybe you don’t need 910 lumens. I have a 150lm candela bulb which uses only 2W, and it’s plenty most of the time. That brings the monthly usage down to 180 watt-hours, or 45 times more than the flashlight approach. Most rooms have more than one bulb though, and rarely use as little as 9W per bulb. So, in a more typical scenario, it’s probably more like 2-4 bulbs at 12-20W each, so overhead lighting (with CFLs ) can be more like a thousand times more energy than the flashlight.

So, at a rough estimate, using a flashlight can be hundreds of times more energy-efficient than using overhead light bulbs. The main reason is because light bulbs typically emit hundreds of times more light and most of that light is unnecessary when you could instead focus a smaller amount exactly where you need it.

Wow, thanks for doing the math and usage scenarios!

Paulcandy · May 8, 2013, 2:16am

the water, sunshine or chemicals will certainly destroy the performance of the light, and we mainly use the flashlight at night, so it doesn’t matter.

StorminMatt · May 8, 2013, 2:43am

Of course, that still doesn’t explain that rot muddy gas.

kreisler · May 8, 2013, 8:08am

Here is the E12 brightness graph (the E09 should perform the same but it had some debris on the reflector), it is the same as the E09 graph:

What you see are the actual Fenix lumens (if the light were a Fenix light, so to speak). They were measured with UPz new DIY integrating sphere calibrated after his collection of Fenix flashlights:

http://forolinternas.com/viewtopic.php?f=10&t=5955

His sphere can reproduce all Fenix ratings of Fenix flashlights released after 2010. Perfectly Fenix-calibrated sphere. I've got the permission to repost the above graph

elgecko · May 9, 2013, 2:14am

Anyone find a tiny case / holder to house this flashlight as an EDC?

billoz · May 9, 2013, 3:35am

I got one of the E09’s for my wife too after she saw mine. Both being used on Keyrings. It is the red one but looks more pink/purple. She loves it.
I too would be interested in some kind of keyring pouch/holder.

Boaz · May 9, 2013, 5:38am

Tank has always had some of the worst "make you want to vomit PWM"

Tanks foul PWM has become ledgendary ...

I'm a great lover of tank lights but this is a serious flaw that takes a great light and makes it an OK light . If they refuse to fix the problem then maybe they need to stick to one mode lights. The $5 thrunite ti still makes more sense...(even though I dislike thrunite for their spamming /shilling activities on blf )

kreisler · May 9, 2013, 6:09am

2 Victorinox mini pouches should fit:

Vinox key fob pouchtoo cheap material dont even go there

Vinox hang pouchtoo short, for 58mm SAK's

Backpacker_Light · May 10, 2013, 3:28am

Am I the only one here that totally disagree’s that PWM is a “serious flaw”?

I do not even notice it on my PWN lights. If it is even worse on my E09 just because it is a Tank brand, I can’t tell.

I find shining the light on water falling from a shower head strangely entertaining, but other than that, the light is the same as all my others.

Does PWN possibly effect the eye’s of some more than others? Boaz, it sounds like PWN gives you a serious headache!

BanglaBob · May 10, 2013, 4:01am

Backpacker Light:

Boaz:

Tank has always had some of the worst “make you want to vomit PWM”

Tanks foul PWM has become ledgendary …

I’m a great lover of tank lights but this is a serious flaw that takes a great light and makes it an OK light . If they refuse to fix the problem then maybe they need to stick to one mode lights.

Am I the only one here that totally disagree’s that PWM is a “serious flaw”?

I do not even notice it on my PWN lights. If it is even worse on my E09 just because it is a Tank brand, I can’t tell.

I find shining the light on water falling from a shower head strangely entertaining, but other than that, the light is the same as all my others.

Does PWN possibly effect the eye’s of some more than others? Boaz, it sounds like PWN gives you a serious headache!

I do notice that my E09’s have strong PWM when I point it at the ceiling fan, but other than that I’m not particularly sensitive to it. I guess some folks are more sensitive to that than others.
For example, I’m really sensitive to (relative) pitch. The tiniest variation of pitch (sharp/flat) and I’m cringing. That’s why I ~~don’t like~~ hate karaoke J) . You’d have to put a gun to my head to get me into a karaoke lounge. Ha Ha !

Backpacker_Light · May 10, 2013, 4:29am

Sorry Boaz. I did some quick research and found out that PWM does effect people differently. PWM does not seem to bother me at all.

Good thread about PWM here….

I never laughed harder than at the video you posted in that same thread (post # 38)

good stuff

ToyKeeper · May 10, 2013, 8:09am

I can see PWM fairly easily, even at frequencies of 4.5 kHz (fastest I’ve been able to try), but it doesn’t really bother me. I actually rather like the really low PWM frequencies sometimes because it works as a makeshift strobe light.

If you want to check a light for PWM, the easiest way I’ve found is to rapidly move a white business card through the beam with a dark background behind. Just wave it back and forth quickly, and you should see either a bunch of discrete frames or a continuous blur.

Oddly enough, I just discovered something while trying this. Much to my surprise, there appears to be PWM on my Zebralight SC52 on L1 (2.7lm) mode. It appears to be partial, though, like… not 0% with brief flashes of 100, but more like alternating between 1 and 5%. Has anyone else noticed this?

never_too_bright · May 11, 2013, 5:27pm

Thanks BBob!
I couldn’t resis and had to get one as well.

Thanks for the write up

NTB

Chloe · May 11, 2013, 7:42pm

Thanks for the warning, Boaz. I don’t have any lights with PWM but I am very sensitive to flickering lights. So maybe I should give this one a miss.

fyesilova · May 11, 2013, 9:15pm

I have this from a BLF giveaway and to my surprise it performs very well with eneloop aaa.
This makes it a perfect gift aaa light.

Racer · May 14, 2013, 2:45am

It looks neat, but I wish it didn’t have PWM. At least the ES12 looks like it has constant current.

kreisler · May 14, 2013, 6:22am

i have ES12. it has de same driver as E09 :)

Racer · May 14, 2013, 7:17am

It’s not constant current, then?

On the CPF thread the OP posted the specs, which has the following line:

Output Levels: 3 mode (Constant current circuit chip which maintains constant brightness)

kreisler · May 14, 2013, 7:28am

this is a joke of a "review", nonetheless it contains good pointers, you only need to follow the embedded links in it:

Boaz · May 15, 2013, 12:19pm

Yeah I am sensitive to low PWM . The new car taillights just freak me out with long trailing red comet tails . I can deal with higher PWM and still know it's there and not get all crazy about it . I have a few lights I like really well that have cool Ui's that have lower pwm and just have to deal with it ...So yeah If I have any ability to make that go away I'll take the opportunity to do so...IMO lifes too short to deal with flashies or funky PWM if you don't have to ..

That said ... The tank lights have always been some of my favorites because of their excellent design and quality bodies ..

run them on high :P