# Faraday cage for my iPhone. **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 24, 2014, 2:08am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835 "2014-04-24T02:08:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [April 24, 2014, 2:08am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/1 "2014-04-24T02:08:51Z")
I am considering buying a Faraday cage for my iPhone (I have my reasons). Saw this on Amazon: [HideCell.](http://www.amazon.com/HideCell-Cell-Protection-Bag-Standard/dp/B00GSZI24M/ref=sr_1_1?ie=UTF8&qid=1398304951&sr=8-1&keywords=hidecell) Seems good but expensive. I know nothing about this technology or this manufacturer. Any info appreciated. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [April 24, 2014, 2:11am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/2 "2014-04-24T02:11:49Z")
[Try this](http://www.amazon.com/Foot-100%25-Recycle-Aluminum-Foil/dp/B001T6EXTS/ref=sr_1_1?s=grocery&ie=UTF8&qid=1398305432&sr=1-1&keywords=aluminum+foil), it’s cheaper. ---
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [April 24, 2014, 2:27am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/3 "2014-04-24T02:27:06Z")
> [@Alley\_Dweller](#): > > [Try this](http://www.amazon.com/Foot-100%25-Recycle-Aluminum-Foil/dp/B001T6EXTS/ref=sr_1_1?s=grocery&ie=UTF8&qid=1398305432&sr=1-1&keywords=aluminum+foil), it’s cheaper. I tried your link but got this: “Bad Request”. Also, how are Faraday cages rated? How do you know when you select a good one, beforehand? What criteria is used? Thanks. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [April 24, 2014, 2:35am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/4 "2014-04-24T02:35:47Z")
It sort of makes the phone useless, though, doesn’t it? ---
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [April 24, 2014, 2:37am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/5 "2014-04-24T02:37:31Z")
> [@beowulff](#): > > It sort of makes the phone useless, though, doesn’t it? That’s the point. I want to be left … Alone … But I wanna leave my phone on 🙂 Again, how do you know when you select a good Faraday cage beforehand? What criteria is used? Can I measure if my device is “peeing” (sending) after being put into a Faraday cage? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [April 24, 2014, 2:44am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/6 "2014-04-24T02:44:12Z")
> [@Little\_Pig](#): > > That’s the point. I want to be left … Alone … But I wanna leave my phone on 🙂 > > Again, how do you know when you select a good Faraday cage beforehand? What criteria is used? Can I measure if my device is “peeing” (sending) after being put into a Faraday cage? Well, you know that doing this is going to kill your battery life, don’t you? Why don’t you just put it in Airplane mode? ---
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [April 24, 2014, 2:47am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/7 "2014-04-24T02:47:41Z")
> [@beowulff](#): > > Well, you know that doing this is going to kill your battery life, don’t you? > Why don’t you just put it in Airplane mode? Why would it kill my battery life? Seriously, I don’t about know about this. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [April 24, 2014, 2:55am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/8 "2014-04-24T02:55:01Z")
> [@Little\_Pig](#): > > Why would it kill my battery life? Seriously, I don’t about know about this. Because the cellular radio in the phone will constantly be broadcasting on it’s highest power, in it’s hopeless quest to reach a cell tower and register. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [April 24, 2014, 3:03am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/9 "2014-04-24T03:03:36Z")
Yep. Cell phones vary the power of their transmitter, using the lowest setting possible that allows them to still talk to the cell tower in order to save battery life. If the phone can’t find a tower it’s going to keep broadcasting at its highest power level to try to make contact. It will drain the battery fairly quickly. Why not just turn the phone off? If you absolutely insist on doing something silly, any completely enclosed metal container acts as a Faraday cage. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [April 24, 2014, 3:08am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/10 "2014-04-24T03:08:47Z")
Sorry about that. Let me try again: [Try this.](http://www.amazon.com/Reynolds-Wrap-Heavy-Duty-Aluminum/dp/B0014D0TB2/ref=sr_1_2?ie=UTF8&qid=1398308843&sr=8-2&keywords=aluminum+foil) ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [April 24, 2014, 3:11am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/11 "2014-04-24T03:11:06Z")
I would have advised just removing the battery from your phone, but regrettably Apple products do not have easily-removable batteries, so I see your problem. ---
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [April 24, 2014, 3:12am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/12 "2014-04-24T03:12:45Z")
> [@Alley\_Dweller](#): > > Sorry about that. Let me try again: > > [Try this.](http://www.amazon.com/Reynolds-Wrap-Heavy-Duty-Aluminum/dp/B0014D0TB2/ref=sr_1_2?ie=UTF8&qid=1398308843&sr=8-2&keywords=aluminum+foil) LOL! ---
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [April 24, 2014, 3:16am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/13 "2014-04-24T03:16:16Z")
I want to “slip” by a really small area. Note: Nothing illegal here. Does turning off my phone really turn it off? Example: When I turn the phone off, I still get notifications of messages sent to me. Missed phone calls, etc. ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [April 24, 2014, 3:16am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/14 "2014-04-24T03:16:19Z")
> [@Alley\_Dweller](#): > > I would have advised just removing the battery from your phone, but regrettably Apple products do not have easily-removable batteries, so I see your problem. They do, however, have easily accessible “off” switches, which seems a lot easier. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [April 24, 2014, 3:20am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/15 "2014-04-24T03:20:34Z")
> [@TimeWinder](#): > > They do, however, have easily accessible “off” switches, which seems a lot easier. Does the off switch really 100% turn it off and disconnect power or does it simply blank the display and put it into a low-power standby mode? If you are really concerned about being tracked or whatever, how can you be sure? ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [April 24, 2014, 3:21am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/16 "2014-04-24T03:21:51Z")
> [@Little\_Pig](#): > > Does turning off my phone really turn it off? Example: When I turn the phone off, I still get notifications of messages sent to me. Missed phone calls, etc. No you just aren’t turning the phone off. You are probably just turning off the screen. Hold down the top button till you get “a slide to power off” screen and slide the button. Now it is actually off. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [April 24, 2014, 3:25am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/17 "2014-04-24T03:25:00Z")
> [@Little\_Pig](#): > > I want to “slip” by a really small area. Note: Nothing illegal here. > > Does turning off my phone really turn it off? Example: When I turn the phone off, I still get notifications of messages sent to me. Missed phone calls, etc. If you mean when you press the off button really quick and the screen goes dark, your not powering off the phone, but basically putting it to sleep and shutting off the display. To power off the phone for real, hold that button down until the slide bar appears to shut your phone off. After you swipe that, you’ll see a little spinner as it shuts down then it’ll go black and won’t transmit or receive. ETA: Ninja’d! ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [April 24, 2014, 3:26am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/18 "2014-04-24T03:26:26Z")
> [@Alley\_Dweller](#): > > Does the off switch really 100% turn it off and disconnect power or does it simply blank the display and put it into a low-power standby mode? If you are really concerned about being tracked or whatever, how can you be sure? How can you be sure it doesn’t have a backup battery, capacitor, or self-contained GPS repeater? At some point you just have to trust, and realize that you’ll sometimes be wrong. In any case, as mentioned, “clicking” the power button on an iPhone/Windows Phone/most Android phones just locks the device but leaves it on (what you usually want). Holding it down for a while will turn it off or give you the option to turn it off. ---
**Author:** ![picker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/picker/32/13969_2.png) [@picker](https://boards.straightdope.com/u/picker)\ **Post date:** [April 24, 2014, 3:29am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/19 "2014-04-24T03:29:44Z")
If you want to be really safe for a short time, put it in airplane mode (to stop transmission/reception of signals) and then wrap it in foil and place in a small metal box (to physically prevent any EM from escaping/entering regardless. Maybe even a mylar pouch would do the trick. ---
**Author:** ![SeaDragonTattoo](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@SeaDragonTattoo](https://boards.straightdope.com/u/SeaDragonTattoo)\ **Post date:** [April 24, 2014, 3:31am UTC](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835/20 "2014-04-24T03:31:18Z")
The “off” option, as in power off, really does turn the phone all the way off. You have to select the option separately from just a quick sleep mode press on the power button. Airplane Mode turns the antenna off, so you can’t talk, text, web surf, or anything else that requires connectivity or Bluetooth. You can, however, still play video games and play music and keep track of the time, calendar, and appointments/reminders. It saves battery because it’s not trying to continually connect to any cell towers. [Next page](https://boards.straightdope.com/t/faraday-cage-for-my-iphone/686835.md?page=2)