Existing users, 
Optimizing iPhone battery life: Between charges and before replacement
Posted 9 July 2007 @ 11am in Guides/How-Tos
Issues surrounding the iPhone’s battery are understandably contentious: the device uses the same non-user-replaceable model as the iPod, meaning that after a certain number of charge cycles (approximately 400, according to Apple) you will need to send when capacity diminishes to an unacceptable level, you will need to send your phone to Apple and pay $86 — a service fee of $79, plus $6.95 shipping — to replace the battery (or use a third-party service like the one offered by iResQ). [Correction/clarification: The battery will lose capacity after 300-400 charge cycles, not fail completely. So technically you don't need to send the unit in if you can deal with diminished battery life. Apple says the battery will retain up to 80% of its original capacity after the 300-400 charge cycles and adds "You may choose to replace your battery when it no longer holds sufficient charge to meet your needs."] All data stored on the iPhone is erased in the process. As such, maximizing the amount of time before replacement is necessary is of substantial concern. Users are also seeking to extend the time between iPhone charges by reducing power consumption, so we’ll attempt to address both issues.
Extending the overall life of the battery (time before replacement)
The iPhone uses a rechargeable lithium ion battery. It’s resistant to overcharging and doesn’t need to be fully drained and then recharged (cycled) with any type of frequency.
Use shallow charges — for the most part You should generally use a shallow charge with your iPhone to extend battery life. Avoid draining the battery entirely (a “deep discharge”) before recharging if at all possible. That said, the battery indicator can become inaccurate if the device is never fully cycled. If your iPhone starts shutting off prematurely (without any low-charge warning, or while the indicator still measures significant charge), try draining the device completely — until it shuts off — then charge it back to full capacity.
Avoid extreme temperatures As noted on this Apple page, the battery works best works best in a temperature range of 32° to 95° F, and should be stored in environments of -4° to 113° F. This means you should avoid leaving the iPhone in a hot car or in areas exposed to direct sunlight.
Also, note that while the iPhone’s battery is largely resistant to overcharging, leaving the device connected to external power for extended periods of times can cause it’s temperature to rise significantly, potentially reducing overall battery life.
Apple: “use the iPhone regularly” Apple recommends that iPhone owners use the device regularly, saying “it’s important to keep the electrons in it moving occasionally.”
Make sure your battery isn’t defective We’ve received reports from some users reporting that their iPhones do not fully charge or take an extraordinarily long time to fully charge. Note that the iPhone has a “quick charge” feature, whereby the battery will charge from 0% to 80% in the same time that it takes to go from 80% to 100%. Both periods should be about 2 hours, for a 4 hour total charge time, on average. Also, note that a plug icon should be displayed when your iPhone is fully charged. If your iPhone takes 10 or more hours to fully charge and never displays a plug icon, first try restoring the device. Failing that, you may want to considering contacting Apple for possible repair, maintenance or replacement.
Extending the time between charges (reducing power consumption)
Use Airplane mode when appropriate If you don’t need phone or Internet access (when you’re simply listening to music or watching a movie and don’t want to be interrupted, for instance), consider put your iPhone in Airplane mode. This will shut off several internal components, dramatically increasing overall battery life.
Check settings, turn off functions Use the Settings application to turn off any features you aren’t using. If, for instance, you’re in an area without accessible Wi-Fi hotspots, tap on Wi-Fi and drag the slider to Off. If you’re not using Bluetooth, tap General, then Bluetooth and slide the function to Off.
Reduce brightness, use Auto-Brightness The iPhone’s beautiful screen is its biggest power glutton. Tap the Settings application, then tap Brightness. Use the slider to reduce overall brightness to an acceptable level, and turn the Auto-Brightness function On — this will automatically adjust screen brightness based on ambient light conditions.
Don’t persistently check for mail The Monday after the iPhone’s launch (three days of usage), one of our staff members’ unit still had a remaining charge, while the other’s had been recharged several times already. The primary difference? The latter individual’s iPhone was checking email from several account every 15 minutes. Reducing this interval to every hour (In Settings, choose Mail then tap Auto-Check) or Manual significantly increased battery life. If you are going to use a short mail-checking interval, tap the Sounds pane of Settings and turn the option for New Mail off.
Turn off keyboard clicks If you frequently use your iPhone’s keyboard, navigate to the Sounds pane of Settings and turn the option for Keyboard clicks off.
Set a low Auto-Lock Go to Settings then select General, then Auto-Lock. The lower this setting (in minutes) the sooner your iPhone will go into locked mode, which turns off the screen and other functions, saving significant battery power.
Turn off the equalizer Apple recommends turning off the music equalizer if you don’t use it. “Adding EQs to playback uses more of your processor, since they aren’t encoded in the song. If, however, you’ve added EQ to tracks in iTunes, you’ll need to set EQ to ‘flat’ in order to have the effect of “off,” because iPhone keeps your iTunes settings intact.” You can access the equalizer option by tapping iPod in Settings, then tapping EQ. Select the option Flat to reduce power consumption.
Feedback? info@iphoneatlas.com.
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8 Comments
Posted by macavenger
9 July 2007 @ 1pm
From the article: “…All data stored on the iPhone is erased in the process.” One question: WHY? the iPhone uses flash memory, which is non-volatile. Removing the battery would not affect the data in any way-unless, for some reason, replacing the battery necessitated a full re-format. But why would this be the case? Even if resetting the iPhone was necessary, why would this have to affect all the data?
Posted by genius
9 July 2007 @ 3pm
macavenger: if the iPhone battery replacement program follows the model of the iPod replacement program, then it would be my guess that Apple will be replacing the entire iPhone, not just the battery. This is how iPod batteries get replaced.
Posted by frelkins
9 July 2007 @ 8pm
I just came back from the iPhone seminars this evening at the Apple store in Soho, NYC. There the Apple rep gave out information that directly contradicts some of what you have written above. For example, she said to drain the battery completely the first time. She made no mention of any benefits from “shallow charging.”
So who’s right? You or Apple? Please advise.
Posted by WaltFrench
10 July 2007 @ 8am
All data… is erased … substantial concern.
If you’re using the iPhone as Apple intends, you’re regularly synchronizing all its data onto your desktop Mac/PC. So be sure to sync your iPhone before you send it in for battery replacement, and plan that the first sync after you get it back will take a bit longer. “Meh,” no “substantial concern.”
And regards the data erasure: envision hundreds of iPhones going thru the battery depot every day, and whatever Apple’s intentions, the chance that your phone goes to somebody else. You actually WANT all the data wiped. Apple sez, “you’re welcome.”
Posted by Tedsterr
22 July 2007 @ 7pm
I think you are both right, sort of. Here’s why. I would argue that though the battery is new as shipped and the unit will work out of the box that does not mean it is fully charged, and regardless of indicator light to a certain degree. Apple didn’t say did they, but when I ordered my phone on the 1st, it hadn’t even been built yet? The shipping point according to the online tracking was Shenzhen, CN, and then on to HK, AK, USA, etc.
24 hours for the _initial_ charge before use makes a lot of sense, it does for every other kind of battery so far, including car batteries. (patience is a virtue) I somehow managed not to boot up my unit for about 8 hours, probably because it arrived as I was going to work. Turn the unit completely off. Charge it all the way up - the very first time - and then run it all the way down - the very first time -; After that - as remarkable as the iPhone is, the battery is still just that, a battery so complete discharge isn’t a great idea. Overall I’m surprised Apple didn’t recommend this to save on any unneccessary returns or exchanges.
Posted by pjchi78
23 July 2007 @ 12am
frelkins:
What she said isn’t a direct contradiction. Draining the battery completely is to calibrate the battery, i.e. to help the iPhone properly read how much energy is in the battery. This article recommended doing just what she said when the iPhone shuts off prematurely. Many sources say that this is a good thing to do once a month for Lithuim-ion batteries. It’s true you don’t want to do fully drain the battery frequently, but you don’t want the battery life to be read incorrectly either.
For normal charging, shallow charges are the best way to go. I doubt she was trying to trick anyone by not mentioning shallow charges, but I note that Apple’s battery web pages also don’t seem to mention it. The reason is probably because Apple believes that it’s better to use your product in a way that makes your life easier instead of planning your life around charging a battery and making life harder.
Also, lithium-ion batteries degrade over time no matter what you do. After 3 years, the battery life of an iPhone will probably be a lot worse than it was when it was new, similar to laptop batteries. If you plan to use the iPhone for several years, then you are probably going to have to get the battery replaced once no matter how well you take care of the battery.
http://www.batteryuniversity.com has a lot of credible-looking information about lithium batteries, but be aware that the author works for a company that sells battery equipment.
Posted by Laura1234
26 July 2007 @ 8am
I think I commented on this elsewhere on this site, but apple’s $85 isn’t the only option out there to replace your iPhone battery. The guys at ipodjuice.com already have the service going.
Posted by gracelet
15 August 2007 @ 5am
Just enjoy the iPhone and let it tell you when (or if) a new battery seems to be on its wishlist. Do you sit around all day and wonder if your lawnmower needs a new sparkplug yet? And speculate that when it does, it will be too soon?? It’s not like a sparkplug goes without some notice to the even slightly conscious lawn mower operator. Same with batteries. Gee, why not try to enjoy the day in spite of your dark side.
I have a bunch of iPods and have only replaced a batt in the one I got in Jan 2003. Three different iPods that I got in the fall of 2004 are all still running on their original battery. I just leave them on top of the “charging station” (my microwave) and try to remember to charge up at least one of them every day. I just grab one on the way out the door.
Same thing with my cell phones (I live in a dead zone and have four phones on two plans for coverage in different areas I use them in). I’ve NEVER replaced the batt in a cell phone and a couple of them are four years old.
Personally I feel the big battery-killer behaviors are leaving the device in a hot environment or just not using the device enough to keep the electrons aware of their job in life, which is to just keep moving until they’re really really tired. I’ll notice when that starts to happen. In the meantime, I love the devices that they let me use for a life on the go.