How To Extend iPhone Battery Lifespan

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Don’t Use a Warm iPhone

I like to play video games on my iPhone. After a good hour of gaming, my iPhone starts to warm up. Games and multimedia applications push an iPhone to its limits. Sometimes low-performance apps, such as social media applications, can also push an iPhone to its limits due to sloppy development. When I first got my iPhone 6, a social media app was draining the battery and causing it to get very warm. It was eventually fixed with an update.

When your iPhone starts to get warm, put it in sleep mode and set it on a metal surface. Wait until your iPhone cools before using it. Temperatures as low as 86º F can start to damage your iPhone’s battery. If it feels warm to the touch, give your iPhone a rest.

Charge Your Battery at 80% and Calibrate Battery Periodically

There’s a lot of controversy as to ideal charging methods. I’ve read many different suggestions, most of which are unsubstantiated. There are some wild theories that you should always keep your iPhone battery between 40% and 80%. This seems to be a misunderstanding of different battery care advice, which I will explain later in this article.

According to both Apple and Battery University, it’s a good idea to top off your iPhone’s battery. The last 80% of the iPhone’s charge cycle trickles current to your device. It is designed to improve the lifespan of your battery by minimizing heat. Indeed, Apple is well aware that rapid charging is detrimental, but there is a tradeoff. Users can’t be expected to wait all day for their battery to charge. This would also be a competitive disadvantage for Apple. They found a decent compromise in letting the battery charge faster for the first 80%. The latter 20% is a slower trickle charge.

If you always charge your iPhone before it drops below 80%, it will minimize heat stress to the battery. According to Battery University, partial discharge cycles reduce stress and increase battery lifespan. With a 100% depth of discharge, users can expect 300-500 charge cycles. With 25% discharges, one can expect 2000 – 2500 charge cycles. Even though the charge cycles are more shallow, one can expect more than 5 times as many charge cycles. A 10% discharge cycle provides up to 4700 charge cycles.

Apple doesn’t agree. Their information claims that a 25% charge counts as 1/4 of a charge cycle. Apple may be approximating this estimate. Battery University’s recommendations apply to all lithium-ion batteries. Apple’s information is specific to the iPhone. Battery University presents more detailed and compelling information. I favor their theory over Apple’s. They also don’t make money from replacing batteries and iPhones.

In either event, topping off your iPhone at 80% will minimize heat and stress. The trickle charge uses less current and produces less heat. This will prolong the lifespan of your iPhone.

There is one caveat. Users should calibrate the battery about once a month. This process involves draining the battery, in addition to other steps. For more information on battery calibration, please read “How to Calibrate iPhone Battery”. (continue…)

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10 comments

  1. Why don’t they just allow us to choose between a fast charge and a slow charge? Would that even be possible? I wouldn’t mind if my phone took 8 hours to charge while I’m sleeping if it meant it would stay alive all day long, and I’m sure plenty of people agree with me on that!

    1. This is a great idea. Also, I think they should allow us to only charge to a certain % before it stops like some laptops do. Would be great to turn off charging at 90%. But, great idea about the charging slow overnight. I would really prefer that.

      1. That’s a great idea, but I doubt Apple will implement it. They tend to keep things simple. The only way you could do that would be to estimate how long it takes to charge to 90% and cut off the power with a timer.

  2. “If you always charge your iPhone before it drops below 80%, it will minimize heat stress to the battery. According to Battery University, partial discharge cycles reduce stress and increase battery lifespan. With a 100% depth of discharge, users can expect 300-500 charge cycles. With 25% discharges, one can expect 2000 – 2500 charge cycles. Even though the charge cycles are more shallow, one can expect more than 5 times as many charge cycles. A 10% discharge cycle provides up to 4700 charge cycles.”

    What do you mean by this? Should I charge my iPhone to 100% and then when it’s at 80% charge it again to 100%? I’ve heard that charging your phone to 100% isn’t a good idea and you should keep it just a bit over 80%. Can you confirm this? Thanks and great infos!

    1. I do mention that charging any lithium ion battery to full capacity places it under stress. This is why satellite batteries aren’t fully charged, as it is difficult to get up there and change them. Apple actually accounts for this in their charging system, but even then, it will diminish battery life if you charge it all the way. That said, the tradeoff is that you won’t get as much usage time per charge. I always charge my Apple devices to 100%. They still last longer than they’re useful. Both my iPhone 4 and iPad 2 have been charged this way, and they’re totally obsolete, but the batteries are still in great shape. I do the same with my iPhone 6 and 2017 iPad. My iPhone 6 is about 2 1/2 years old now, and the battery is still in very good shape.

      Charging before it gets to 80% will force it to do a trickle charge. That’s part of Apple’s solution to battery stress at (or near) full capacity. This recommendation is for people who want a fully charged iPhone. If you want to keep an iPhone for several years, then don’t charge it all the way to 100%. I figure the battery could last a decade. I still have my iPad 2, which is 6 years old now, and it can still run 8-10 hours on a full charge. But I always charged it to 100%. Theoretically, the battery would be in better shape if I only charged it to 80% or 90%. I took the tradeoff of enjoying the 8-10 hours of battery life. In the grand scheme of things, it didn’t matter…

      With this article, I am trying to state the facts, and not trying to recommend one specific method of charging an iPhone. Some people may be fine by charging it to 80% or 90%, and yes, it will keep the battery in better shape. But if you want a full charge, it’s best to top it off before it gets down to 80%, when possible.

      The most important thing is to turn off your iPhone when charging. People who have a dead battery after 18 months are usually doing some intensive tasks (games, video) while charging their iPhone. If you turn off your iPhone while charging, it will charge much faster and the battery will stay cool. Your battery will last beyond your iPhone’s usefulness.

  3. Great answer! Really useful information. I just got my iPhone 7 Plus last week and I’m planning to prolong its life to the longest I possibly can. That’s why I’m reading a lot on articles about battery charging tips and none has surpassed the quality of information of this one, really. Just a couple more questions, if I may.

    1. Is it okay if I let my phone discharge to about below 30%? I’ve read I should never discharge my phone too low as it is a bad for the battery. Please enlighten me on this one. If this is true, can I ask why?

    2. How do you personally charge your own phones? Do you let is discharge low and then top them off? If so, how long do you keep it to 100% before unplugging the device?

    Again, thank you so much for this informative article. Keep it up!

    1. 1. Going below 30% is only bad for long term storage. If you run it below 30% and charge it within a few days, that’s not a problem at all. This is because the lithium ions seize if they aren’t holding a charge for a long time (weeks/months). I think a lot of people are confused, because iOS pops up a warning at 20%. That’s just about making sure you don’t run out of juice while you’re using the iPhone.

      2. The irony is that I really don’t follow many of my own recommendations. The main thing is that I turn off my iPhone when charging. That’s the most important thing to do. I typically charge my iPhone when it is below 20% and leave it plugged into the charger for hours. Since it is off, I don’t really know when it hits 100%, but it usually charges long enough to go beyond 100%. I’m not concerned about it overcharging, as the power management IC prevents that. The other important thing is to prevent your iPhone from getting too warm. Don’t leave it in a hot car. Even if it is not charging, if you’re using an intensive app for a long time, your iPhone may get warm. For example, watching video, particularly over a cellular connection, will warm up the phone after a while. Take a break and let it cool down. I also don’t use a case, but that comes with a tradeoff. If I drop my phone, it will probably be damaged. If you use a case, you should at least take it out of the case when charging (and turn it off). The problem with most cases is that they insulate the iPhone. Trapping in heat will diminish battery lifespan. Even Apple recommends taking the iPhone out of its case while charging. If possible, get a metal case, but they usually have a neoprene liner, which traps in heat.

      I’m glad you like the article. You might also be interested in “How to Calibrate iPhone Battery”. Calibration should be done every month or so. I also like to do it after every major iOS update. If you are experiencing unexpected drops in battery life or your iPhone shuts down at 20-30%, calibration will often fix the problem.

      Feel free to share this and any other article. I’m always looking to grow my audience.

  4. I purchased a refurbished iPhone 6s Plus last week. It arrived today and after setting it up, the battery life is at 84%. I’m concerned that it’s so low. I’ve bought only one other refurbished phone – an iPhone SE, which was at which at 93% (and still is). I came across your article and the information was helpful “now,” but it didn’t allay my initial concerns. I would appreciate your input. Thanks.

  5. Thank you very much for your tips. I’m an Uber driver. I find my iPhone battery wears a lot after I use it Uberring for about 9 months. Especially when the weather was getting hot and before I turned on my air conditioner. I usually charge my iPhone all the time when I’m driving. Is it right? Or what’s the more proper way to charge the battery as an Uber driver?

    1. I would recommend not charging the phone while it is in use. This generates a lot of heat, which shortens the battery’s lifespan. Ideally, it should be turned off while charging. It should be removed from any case while charging.

      In your situation, you may just have to succumb to replacing the battery every year or so. I don’t see a better solution. If you got a battery extending case, it would just charge the iPhone while it is in use, and the case would exacerbate the thermal issue.

      As an Uber driver, you pretty much need your iPhone on all the time. The best you can do is to at least wait until it is close to running out of battery life before you plug it in to charge it. This will at least shorten the amount of time it is simultaneously charging and discharging the battery.

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