# Flashlight App for Phones, How long do you dare run it?



## mbw_151 (Oct 19, 2012)

How long would you run a phone app that uses the camera flash LED as a flashlight? Most phones have enough battery to run for a while but seem a little short on heat sinking. As a photo flash, the LED is on for a very short time so heat buildup isn't an issue. I've looked and never found anything from Apple or Samsung discussing this issue. I know lots of people who won't carry even a Photon but carry a phone. I tell them not to run the flashlight app for a long time, but can't put a number on how long is too long. I'd hate to see them smoke an expensive phone.


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## spankone (Oct 20, 2012)

Most modern phones actually turn them selves off when the get hot


Sent from my iPhone using Tapatalk


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## hellokitty[hk] (Oct 20, 2012)

I doubt it'd over heat from that. They don't use too much power even if heatsinking is poor.
But I don't even own one so...


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## Mk1dev (Oct 20, 2012)

I use mine fairly often , and I have been guilty of leaving mine turned on by mistake , but for not much longer than say 20-25 minutes


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## AstralWraith (Oct 20, 2012)

Most of those phones are designed where that LED is more than just a flash. A flashlight on a phone is a critical feature allowing safety in dark areas, finding of objects like keys dropped or the lock on a door at night, signaling if lost of on the side of the road broken down trying to attract a police officer, etc. It does not take much power to run that led compared to the bright led's used to backlight the screen, the screen usually(but not on the newest led technology phones) uses more power than just that led next to the camera being on when the screen is is on its brightest setting, and barely generates much heat compared to the cpu chip. Finally, the led isn't necessarily near the processor, memory, battery, or other heat producing modules to assist with things like this, so I doubt this is really ever an issue unless you know of a specific case you've experienced.
In short, the phones are generally designed structurally to allow for the continuous operation of that led 'camera flash', it isn't actually that power hungry. Your only issue is shortening the battery life significantly, which browsing on the internet does as well and similarly in my experience.


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## Preamp (Oct 20, 2012)

My Sonim XP3.2 does not need an App for use as a flash light. Once it managed to activate itself in my pocket. When I noticed that it became warm, it already sucked all the juice out of the battery. Which is quite a lot, 1.6Wh IIRC. Caused no damage though.


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## Echo63 (Oct 20, 2012)

I don't have a flashlight app on my phone.
i don't use my phone as a flashlight ever.

I have flashlights for that (I carry a flashlight more than I do my cellphone)


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## Bwolcott (Oct 20, 2012)

I wouldnt be scared to use it as long as I wanted it on


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## Erik1213 (Oct 21, 2012)

I know that my iPhone will turn the flash on and leave it on when using the video camera function. I know that it will also disable the LED if it is too hot. I have a flashlight app but I have at least two lights on my person at a time so it never gets used.


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## TMedina (Oct 23, 2012)

The flashlight app is a decent emergency tool, but as others have noted, you're draining power off your (presumably) main point of communication, which could be a really bad idea, especially if you have no easy means of recharge.

That said, I've never heard a report of a phone melting down because of the flashlight app.


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## Blue72 (Oct 23, 2012)

I have used them for hours at a time on several different phones in the past with no problems at all....I am even shocked how much battery life is left after using them for long periods

Maybe we need an official phone flashlight runtime thread for various phones. Any volunteers?


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## sabotage (Oct 23, 2012)

i agree, i dont think its possible to actually melt your phone from over use these days.


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## Sinke (Oct 24, 2012)

I did use it once for 35 minutes. It did heat up the phone a little, but no problems whatsoever.
Except for the huge battery drain.


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## jorn (Oct 24, 2012)

Someone borrowed my phone when we needed to go down from a mountian trip. He had no phone, no flashlight, no nothing.... 3 hours with constant on with no problems, other than my phone was drained.


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## Outdoorsman5 (Oct 24, 2012)

jorn said:


> Someone borrowed my phone when we needed to go down from a mountian trip. He had no phone, no flashlight, no nothing.... 3 hours with constant on with no problems, other than my phone was drained.



Dang, did he at least bring some food, & water......matches, lighter? And, shame on you jorn for being such a flashaholic and not even having a spare flashlight to loan to the unprepared .


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## Launch Mini (Oct 24, 2012)

I wonder if we can get a phone app for our flashlights?


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## mina (Oct 24, 2012)

I'm not afraid to let the LED "flash" run as long as there's juice in the battery.

I don't do it though since I have a light with me most of the time.


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## Preamp (Oct 24, 2012)

Launch Mini said:


> I wonder if we can get a phone app for our flashlights?



... Only if it's useable while in the pocket, or else you'll kinda have to stick it into your ear... :laughing:


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## nbp (Oct 24, 2012)

Will Flashlight Apps Stop the Need to EDC a Flashlight?


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## TMedina (Oct 24, 2012)

jorn said:


> Someone borrowed my phone when we needed to go down from a mountian trip. He had no phone, no flashlight, no nothing.... 3 hours with constant on with no problems, other than my phone was drained.



Dude. You're a better person than I am.


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## jorn (Oct 25, 2012)

Outdoorsman5 said:


> Dang, did he at least bring some food, & water......matches, lighter? And, shame on you jorn for being such a flashaholic and not even having a spare flashlight to loan to the unprepared .



We were only staying the day, and were supposed to go down before night, but murphy's law changed everything. I always prepare for mr murphy  He had food , a fishing rod, and vading pants in his backpack. He was no outdoorsman at all. It was a friend of one of my co-workers. Always complaining on his feets are hurting etc. Dont know what he did expect when showing up in nike air's and sweatpants.. Hahaha i warned him berfore we started walking...We were going on a "fishing extreme" trip as i call it. (I love it in lousy weather. Thats when you got a chanse to fool the big ones to bite.) And the weathecast was saying, lots of rain and strong winds later that day. 

He was actually thinking about just sitting down and refuse to walk anymore after one hour walk DOWN from the mountian. He dident even take off his wading pants, and it naturally got torn by branches and bush. Im have learned my lesson and wont bring "unfit" pepole with me to "fishing extreme" trips anymore. Mr Murphy will kill them  

I had 4 lights. We were 5 pepole, and i were the only one with flashlights, or even a phone. That did suprice me. No light, ok i have seen that many times.. But no phone.. thats stupid.. 
We never bring water, can drink out of every stream and lake around with no problems at all. Unless it's one of those years with too many pest spreading lemmings. Then i use to boil the water first. 

The phone was a little hot, and soaked with water when he gave it back to me down with the cars. I felt really pissed off, but dident say anything. He was in a lot of pain, and i felt it was not the right time to yell at him. It's the oldest version of the crappy xperia mini pro. Still works fine. When pepole with the fancyest iphones ask me why i still use that old crappy phone. I just hold it out and drop it, and say: Your turn  Love my little crappy phone, it have been trough hell so many times but refuse to die on me.


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## Outdoorsman5 (Oct 25, 2012)

jorn said:


> ....I had 4 lights....



Once again, I am very proud of you jorn. Way to be a well prepared leader. Maybe the whole group learned a lesson on being prepared. Did you catch any fish? If I ever get to go back to Norway then I want to go on one of those fishing extreme trips....very cool.


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## jorn (Oct 25, 2012)

No. Dident even catch a small one. That trip was all pain and no gain  But it's always fun to try  The phone really impressed me that day.


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## mat_the_cat (Oct 30, 2012)

Preamp said:


> My Sonim XP3.2 does not need an App for use as a flash light. Once it managed to activate itself in my pocket.


Mine used to do that all the time, so I took a sharp scalpel, and trimmed off a few mm from the button to make it more recessed. Don't worry, there is plenty of material behind so you won't make the phone leak!


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## Preamp (Oct 30, 2012)

Good idea, but that won't work for mine. After about 2 years the GPS stopped working, so I sent it to service. They sent me a completely new unit back. But this one seems to have a different software. The flashlight isn't operated with the side-button, but with the '5' key! Took me a couple of minutes to figure that out, since it's not documented anywhere...


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## Pmbspyder (Oct 30, 2012)

i never use mine for more than 1-2 minutes. more because it drains the battery incredibly fast than anything else...


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## fresh eddie fresh (Oct 30, 2012)

If I need a little light and happen to have the phone in my hands, I just wake it up and use the screen. My flashlight app needs to be turned on and then the level set... it takes about as long to do that as it does to complete whatever task I need it for! (Usually to find a regular flashlight!  )


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## tam17 (Oct 31, 2012)

My phone has neither camera nor flash - it has a dedicated SMD LED though, and sometimes the screen glow is just enough. I've seen people running the flash LED for 2-3 minutes while recording a video. Light intensity is far below still camera flash, and I believe flash app doesn't use the full blast either. It would surely melt the LED if used continuously. But, heatsinking may actually work if phone body is alloy and if any thermal path exists (too many "ifs" here...)

Cheers


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## LightJaguar (Nov 1, 2012)

I think it depends on the intensity of the LED. I've had a few HTC phones that have the flashlight app and have different levels of intensity for the LED. If remember correctly the first time you use it or it might be another flashlight app it warns against extended use of the LED. 
I for one find it much much easier and fun to use my key chain flashlight. Right now it's a thrunite Ti AAA flashlight that is bright and much better for tasks requiring a flashlight. 
I think that on my Droid 2 I had a custom rom where you could assign the camera button to turn on the LED and use it as a flashlight. I think two quick presses and only the LED came on. On my other phones I have to unlock the screen look for the app and use my fingers thumb to navigate through the touch screen. With my keychain I just reach in, grab the flashlight and twist.


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## legtu (Nov 3, 2012)

i've used mine a couple of times maybe 1-2 mins. max. but if need be, i'll let it run as long as it can...


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## AndoDoug (May 1, 2015)

AstralWraith said:


> In short, the phones are generally designed structurally to allow for the continuous operation of that led 'camera flash', it isn't actually that power hungry. Your only issue is shortening the battery life significantly.


This is good to know - I'm currently experiencing a bit of a predicament because I had my flashlight working overtime serving as a desk lamp, the battery got down to nil with the flashlight on, and now the phone is not responsive. When I powered down and restarted, the flashlightturned on before startup was complete, and prevented the reboot from completing! Now it doesn't even get to the flashlight coming on before the phone turns itself off. 
Any suggestions? Cheers on occasion of first post


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## FRITZHID (May 1, 2015)

I've ran and dismantled a few smart phones and the LEDs are surprisingly well heatsinked in Most cases, as well as the fact that they are usually underpowered. A few phone apps pwm the flash (my s5 does this) when used as a light but runs slightly brighter when taking a pic.


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## JasonJ (May 6, 2015)

I've used my phone as a flashlight in some cases. Before Apple added the option within iOS I had an app to do it, and it had a variable slider for light output. THAT was nice because I could get down to those moonlight mode levels. I never have had to use the phone LED as a flashlight for more than perhaps 30 seconds to a minute. If I need to go more than that, or actually light up an area (anything other than looking for my glasses or shoes in the middle of the night) I use a real flashlight. 

Ironically, I've used my phone LED flashlight to search for one of my EDC lights that rolled away. It was more convenient than firing up one of the other 3 lights I usually have with me.


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## Fleetwood (May 6, 2015)

I have an HTC Desire S with a cracked screen that I don't care about. I might leave it on charge in the garage with a Flashlight app open for a few days and see what happens!


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## markr6 (May 6, 2015)

Not sure if it was mentioned, but the iPhone doesn't need an app...it's a feature built right into the menu.

So, I would think that means you could run it quite some time, if not until the battery was dead without any problems.


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## MidnightDistortions (May 6, 2015)

Only if necessary. If i got a working flashlight i'll use that instead .


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