Maximise your iPhone’s Battery Life : Part 1

Empty iPhone Battery

Is your iPhone battery not lasting as long as it should/used to? This is the first of two blog posts on getting the most out of your iPhone’s battery, this time we’ll focus on the hardware side.

The conventional wisdom for taking care of your batteries, wether it be for your smartphone or the rechargeable AAs in your TV remote, is to charge them up to 100% and down to 0% rather than frequent bouts of charging. Unfortunately, this is in direct contradiction to the advice given by the experts[1].

You may have come across the term ‘cycles’ when talking about batteries, in short this describes one full charge and a corresponding full discharge, Apple rates their iPhone batteries to retain up to 80% of their original charge after 400 full cycles[2], although from our experience we expect this is under favourable conditions. With use, Li-ion batteries such as those found in iPhones will degrade and lose their capacity or ability to fully charge. The following graph illustrates how 11 common 1500mAh Li-ion batteries drop capacity as they are cycled.

Li-ion battery degradation graph

Notice how the starting capacity is between 88-94%

The level of charge your battery falls down to during use (or to give it it’s technical term: Depth of Discharge or DoD) corresponds to the lifespan you’ll get out of it, so try to avoid fully draining the battery and charge it more often. The following table illustrates how many cycles a Li-ion battery can provide at different depths of discharge:

Cycle capacity at different depths of discharge

As shown, a low depth of discharge will keep your iPhone’s battery alive for quite a bit longer.


Recommended iPhone Temperatures


Another considerable factor is the temperature your iPhone’s battery is exposed to, heat puts stress on Lithium-Ion batteries and will cause them to lose their available capacity. Apple recommends keeping your iPhone between 0° – 35° Celsius, and although iOS will display a warning sign and temporarily disable your iPhone until it cools down if it senses it’s getting too hot we’d recommend not leaving it out in the sun for too long! (The adhesive used in iPhones, iPods & iPads is heat activated and we’ve seen the results of leaving an iPad out in the sun whilst on holiday for too long.)


Of course the Li-Ion batteries in your iPhone do have a finite lifetime and these measures can only go so far to prolong it, if you’re struggling with an iPhone that won’t make it through the day, we offer affordable battery replacement services for your iPhone 4S, 4, 3GS & 3G. Feeling adventurous? We also sell standalone original iPhone parts, including batteries.

To recap:

  • Charge your iPhone’s battery frequently
  • Try not to let it drain completely
  • Keep it cool!

In part 2 we’ll focus on the software side of battery care. 

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