01Feb 2016

Ask smartphone users about their battery experience and you often get the typical answer: “it sucks!” But why? and what is the problem?

iPhones suffer from a small battery capacity, so it is understandable that Apple users get upset with their short battery life. But the Android phones? Most boast of larger batteries, in fact much larger batteries, that tend to do exceptionally well when they are new. Browse the web and you will find that many Android smartphones, when tested new, do give the consumer a full-day of use. So, again, what is the problem? and what leads the consumer to wake up after a few months of use  bewildered about the battery life that evaporated? This post is for you if you experienced this battery problem.

I posted last year, on 27 March 2015, a blog on testing a brand new Samsung Note 4 and its battery. Samsung was proud about introducing fast charging in this device…”50% in about 30 minutes,” Samsung claimed. The fresh battery was tested at the time to have a charge capacity of 3,185 mAh. One of my colleagues used this phone as his primary device since then. He recently complained about not getting a full day of use from his device, so we tested the battery this past weekend. What did we find?

After 310 days of use, the measured battery capacity is 2,591 mAh, or 81% of the original capacity less than a year ago. Ouch! Samsung, that really hurts! Samsung did not tell the consumers that fast charging was killing their batteries.

This is all explained in the next chart showing the capacity of the same Samsung Note 4 battery fresh as measured in March 2015, and after use in January 2016. The vertical axis shows the measured battery capacity in mAh as the battery is charged using the Samsung AC adapter. The horizontal axis is charging time. For the techies among you, both were charged to a cutoff current of C/20 at room temperature.

Samsung Note 4 battery

After 310 days of regular office and personal use (this device was not abused and was not exposed to extreme conditions), the battery’s capacity dropped to 2,591 mAh, or 81% of its initial capacity. In other words, 594 mAh of capacity were lost! That’s somewhere near 3 to 4 hours of use in one day that evaporated! In technical terms, a battery at 80% of initial capacity is deemed dead and in need of replacement.

That’s the pain that consumers feel after using their devices for a few months, but can’t really articulate the nature of their problem. It is simple: Some smartphone OEMs do not want to publish that their batteries lose capacity with time, or worse yet, that their claims of fast charging are damaging the batteries. As a consumer, start paying attention to the battery specifications. Ask for the capacity figure; ask for how fast it charges; and equally important, ask about the cycle life of the battery. That’s a measure of the battery’s longevity and a measure that you will not be disappointed with your purchase only a few months down the line.