Understanding your iPod/iPhone batteries lifecycle

Author: Shane Jordan

1 Oct

Probably the most common type of iPod/iPhone repair involves the replacement of their batteries. While some batteries may fail with a year or less of use, more typically batteries last anywhere from one to three years. Customers often ask me, “What causes my iPods battery to die?”. And thats a fair question. iPods use a type of battery technology called Lithium ion. Lithium ion batteries have a limited lifespan of between 300 and 500 charge cycles. A complete cycle is using your iPod/iPhone from a full charge, all the way to when the iPod/iPhone shuts off when the battery is completely drained. Assuming you are someone who uses your iPod/iPhone everyday, or nearly everyday, 300-500 cycles will get you anywhere from one to three years of usage. Super heavy users may wear out the batteries in a year or less, and your grandmother who listens to Elvis once a week might take 5 years to reach 300 cycles. What I usually tell customers is that your iPods battery should last at LEAST one year. If not, I would consider it defective. The same goes for our replacement batteries. In addition Lithium ion batteries should be conditioned regularly. What do I mean by conditioning? Lithium ion batteries can suffer from a strange affliction whereby crystals can develop in the unused portion of the battery. Lets say for example that you fully charge your iPod everyday and then use its battery halfway the following day and repeat charging it. The 50% that is always charged will begin to develop crystals which will limit that portion of the batteries ability to properly and reliably provide power. To prevent this, regularly fully discharge your iPod/iPhone and completely charge it up. This is not necessary everytime you use your iPod/iPhone, however this should be done at least once a month. Even simple maintenance such as what I just explained can help you to see a noticeable increase in both battery life and battery longevity. Please continue to check back regularly for more articles on keeping your iPods and iPhones in tip top shape, preventing problems, and fixing issues when they do occur.

Filed under: iPhones, iPods

3 Responses for "Understanding your iPod/iPhone batteries lifecycle"

Eliakim October 2nd, 2007 at 10:26 am 1
I thought the “memory effect” was “history” and didn’t come into play any longer, with these newer kinds of batteries, like the lithium ion ones. So, we are back to the same ole stuff of constantly conditioning the batteries to make them last longer? I just ask that because other places say that this is not necessary. You just don’t know what to believe any more these days…
Pecos Bill October 3rd, 2007 at 4:40 pm 2
Yes, you describe battery memory. Lithium batteries are memory free. Apple tells users to condition their Mac batteries for a totally different reason: re-education of the battery management circuitry inside the battery so it can accurately report remaining capacity (it dwindles as the cycle count increases) and properly manage it.

Supposedly and according to Apple, each charge cycle does not count as full cycle unless it’s fully depleted but is a sum of the partials. Speaking of full depletion, it’s not good to leave any Lithium battery depleted for any time and it’s best not to store one fully charged either.

See http://www.apple.com/batteries/notebooks.html and/or http://www.apple.com/batteries/ipods.html for good info. I would add to the part about storage that you should store it in a refrigerator (NOT freezer–use for alkalines only). I did that with my extra battery for my 2001 iBook and it still has excellent life.

Make sure to warm it to optimal temp before using.

Lastly, I suggest doing a google search on lithium battery care and pay attention to who is saying it. Trust entities that work with the technology before trusting a site that does not.
Thom October 15th, 2007 at 2:21 pm 3
300-500 full cycles and it’s dead? Sorry, that’s not what the documentation says.

After about 400 full cycles, the battery is expected charge to 80% of its original capacity. It should be quite clear 80% is not zero. Furthermore, this is a gradual reduction.

So, currently the battery provides about 8 hours talk time, about twice that of the 4 to 5 hours of other phone. After about 400 full discharge cycles one could expect about 6.4 hours, which is still more than other phones. Also keep in mind other phones use similar batteries, and their 4 hours of talk time would be reduced to about 3.2 hours at that point.

Let’s keep this in perspective.