How Long Does a Cell Phone Battery Last?

Michael Kwan
phone with low charged battery

Of all the features and specifications found in modern day smartphones, the one that is possibly the most overlooked but arguably also the most important is battery life. There can be a lot of variability between devices, both in terms of how long they last between charges and how long until the battery should be replaced.

Day-to-Day Usage

The day-to-day battery life of a contemporary smartphone will depend on a number of different factors.

  • Phones with larger, higher resolution displays will typically consume more power than devices with smaller, lower resolution screens.
  • Phones with larger batteries tend to last longer.
  • If your phone is constantly hunting for cell phone signal due to poor reception, your battery life will suffer as a result.

How you choose to use your phone will also naturally impact the time between charges. Data-intensive apps and games consume more battery than sending periodic text messages, for instance. Other factors include screen brightness, using additional features like GPS and Bluetooth, and the power requirements of the processor.

Battery Tests

The battery test used by Tom's Guide involves continuous web surfing while on the 4G LTE network of T-Mobile. In its list of smartphones with the longest battery life, results with continuous surfing were:

  • The ZenFone 3 Zoom from Asus came out on top at 16 hours and 46 minutes.
  • By comparison, the Google Pixel 2 came in 23rd place with 11 hours and 7 minutes.

Most new smartphones can usually last a full day on a single charge with moderate usage, but this will depend on individual circumstances.

Cell Phone Battery Life Span

Just as the time between charges can vary considerably, the same is true for how long a cell phone battery can last before it has degraded significantly and needs to be replaced. The typical lithium-ion batteries used in today's smartphones can continue to hold about 80 percent of their original capacity after 300 to 500 charging cycles. A charging cycle is sometimes defined as going from a full charge (100 percent) to completely empty (0 percent) and back up to a full charge again.

Life of Approximately One Year

Given these figures, some experts assert that smartphone batteries are really only designed to last about a year writes Business Insider (BI). In this context, a "charging cycle" may be defined as any time you plug in your phone for charging when the current battery level is below 70 percent.

At the same time, since most people do not wait until their cell phone batteries are completely drained before recharging back to 100 percent, some experts say the battery will last up to 2,500 charging cycles before it is "permanently damaged for the harsh effects a full-discharge has on a battery" according to BI.

Diminishing Charge Hold Over Time

Whatever the case, it is generally true that as a battery undergoes more and more charging cycles, its ability to hold a charge will diminish over time. Deciding when it is time to replace the battery is a personal choice as you may decide to replace your phone after two years or more anyhow.

Apple iPhone Battery Replacement

To help mitigate or reduce the effects of diminished battery replacement in its iPhone series of devices, Apple delivered a software update to iOS 10.2.1 in 2016. Part of the update was designed to improve "power management during peak workloads to avoid unexpected shutdowns" on older iPhones. This reduced the maximum performance on affected iPhones in response to the inevitable degradation of the phone's battery.

As this information was made available to the general public, Apple decided to reduce the price of a battery replacement on an iPhone without warranty from $79 down to $29. With a new battery installed on the older iPhone, normal peak performance is presumably installed. The battery replacement program experienced some issues as demand outstripped supply.

Regular Wear and Tear

Just as tires, wipers and batteries need to be replaced regularly on automobiles, the battery inside a cell phone undergoes a similar kind of regular wear and tear. How you choose to charge your phone can impact the life span of the battery too. It's better to charge in small bursts, for instance, and avoid keeping your phone plugged in when the battery is already full.

How Long Does a Cell Phone Battery Last?