Help with iPhone battery power

http://www.adventurealan.com/iphone4gps.htm

I just described what I do in this thread.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=98173

I don't know whether some of the things like disabling background refresh are redundant, i.e. whether locking the SIM effectively disables them all anyway. If you care that much about taking a few extra seconds to adjust a few settings before you set off on a hike, you'd have to test for yourself whether it makes a difference. But I know what I do works.

So really the question is what is redundant? If the Sim is shut off in effect anything that used cellular/data is off right? So do you still need to turn everything else off? Same with airplane mode it shuts everything down as well. Is one way better than the other or does in not make a difference? I have been just using airplane mode but it still drains pretty quick compared to what others are doing.

(1) Cell functions, especially searching for non-existent cell towers, is by far the biggest power drain.

(2) Using GPS alone is a moderate power drain (order of magnitude 5% battery per hour).

(3) Pretty much everything else – occasional camera, browsing maps without GPS, occasional audio – is a modest power drain, and can easily give you over a week of battery life. Unless you're watching movies, it takes surprisingly little power to drive the screen.

Turning Flight mode ON will always switch off cell & GPS. So if you're not using GPS, that always gets you into battery conservation mode with one quick action.
However, the ONLY way to use GPS without the cell functions coming on is to lock the SIM. Then Flight mode just toggles the GPS chip off/on.
This is by far the most important thing to set up correctly, and it's probably all you need to do unless your concerned about the last few percent of battery life.

The other minor additional settings are going to be relatively small effects, I think. I just do them when I'm off into the middle of nowhere for a week, and I want to be absolutely sure I'm getting the most from my battery. Like, say, I don't know if "Find My iPhone" really drains any power when cell functions are off. Since these are minor tertiary effects, I think nobody has thought it worthwhile to really test carefully. If you want to spend a few weeks doing careful controlled experiments with the settings go right ahead… but I think it's easier just to make a checklist for all the settings. It takes me about 60 secs to optimize my phone before I leave on a hike.

So lock the SIM and put in airplane mode for just sipping power. Turn off airplane mode to use GPS. Thats it? Leave all other settings as is for normal everyday life? Thanks for the help

Exactly. That will cut out the majority of the unnecessary power drain from cell service.

Only if you're heading off into the middle of nowhere and want to be completely sure that nothing else is sucking even a smidgeon of power, then just run through that checklist I put up on the other thread.

"So lock the SIM and put in airplane mode for just sipping power. Turn off airplane mode to use GPS. Thats it? Leave all other settings as is for normal everyday life? Thanks for the help"

With the 5S, you can skip the SIM lock step. Unfortunately power drain with the SIM lock on is the same as with it off. That wasn't the case on older models, but for some reason it changed. Just leave it in Airplane Mode (and obviously keep WiFi and Bluetooth off) and don't turn on the display more than you need to. And turn it off completely at night. That's about it.

I never had a 5S, but I had a 5 and I now have a 6. They both work in exactly the same way, and have exactly the same power drain characteristics – i.e. locking the SIM disables the cell services but does not switch off the GPS chip. Are you saying that this is not the case with the 5S, that Apple changed something and then changed it back? That seems implausible. I'm wondering if it's related to the way the phone is specified for the particular carrier – I have always had a Verizon phone, and I've heard that other carriers may not work the same way? What carrier are you using?

Oh, it does switch off cell service. You won't be able to use the cellular radio at all. But it still drains the battery at the same rate. Strange but true. The above link to Adventure Alan's page reports the same behavior with the iPhone 5.

To my mind that's definitely a bug, and I've filed a report through Apple's feedback site. I haven't heard anything, but I also haven't retested since upgrading to iOS 8 so I suppose they may have fixed it.

But, to repeat my question – which carrier are you using? The problem cited on Adventure Alan's page is with an AT&T iPhone5, and I've heard before that different carriers seemed to have their iPhones specified differently.

I should have made clearer perhaps that my usage experience and recommendations were all with Verizon. I have not heard of any issue with Verizon phones, whether 5, 5S or 6, using any OS. I've used my Verizon iPhone 5 with all recent OS's and my Verizon iPhone 6 with iOS8 and they all behaved identically.

I'm on T-Mobile now, formerly on Verizon. I never had the option to SIM lock on Verizon because I only had the CDMA model iPhone 4. Do the CDMA/GSM dual radio models disable the CDMA radio when the SIM card is removed?

I've only owned the 5s for about a week so can't really say how it will perform. I've taken both a ATT and Verizon 4s backpacking. I've never locked the sim on the ATT phone or have done anything more than putting the phone into airplane mode. Just checking Gaia a few times per day, I can milk a week out of the phone. If I'm taking a lot of pictures and video with it, I plan on recharging it once every four days. iPhone batteries seem to noticeably lose their ability to hold a charge somewhere between 18-24 months.

"So lock the SIM and put in airplane mode for just sipping power. Turn off airplane mode to use GPS. Thats it? Leave all other settings as is for normal everyday life? Thanks for the help"

Yes. By locking the SIM, it prevents the phone from searching for a cell tower when you turn off Airplane mode to use GPS. Also, turn down your display brightness, and turn off your wifi and bluetooth.

Mike, I agree from experience that this work with Verizon phones – I've used Verizon iPhone 5 & 6.

Mitchell's comments raise the issue that other carriers may have iPhones configured differently. The SIM card lock is a workaround for the fact that Apple settings don't provide a simple way to switch the GPS chip on independently of the cell functions. I don't know how all this relates to CDMA/GSM/LTE technologies, and I've never found any clear explanation of this.

It might be helpful if everyone commenting & recommending methods could include phone model & carrier in their comments.

Ok just did a day hike and shut down the SIM and put in air plane mode when not using the GPS with Gaia. BTW Verizon 5S. some drain over three hours but much better than normal. I do not have service where I hike so definitely a battery saver. I turned off BT, wifi and screen was dimmed down too. While using Gaia i did not use tracking just location but still drained about 15% of the battery just checking every so often. I'm still baffled at how people are getting a week, I might get 3 days not using apps video, camera or music. Still testing. Thanks guys

I've never tried to make my phone last a week. If I wasn't going to use it much then I'd just save the weight and leave it home. But I use my phone for photos during the day, some browsing at maps, and maybe reading at night. I charge from a battery pack in the evening before going to sleep. For longer trips I'd take a solar charger to charge the battery pack during the day.