All about battery and charging

Charging habits to maximize battery life

Smartphone users- casual and enthusiast alike are forever in search of longer battery life. While fast charging keeps us topped up every day, the absence of replaceable batteries means eventually the lithium-ion cells enclosed in our phones are going to age and deteriorate.

If you've held onto a phone for a year or more, you've probably noticed the battery doesn't seem to last as long as it did when it was brand new. Two years down the line and many phones struggle to make it through the day on a single charge. Holding onto a phone past three years can even spell trouble for system stability.

One particularly persistent battery myth is that you need to occasionally fully discharge and recharge to erase "battery memory." This couldn't be more wrong for lithium-ion batteries. It's a leftover myth from lead-acid cells and it's actually quite undesirable to charge your modern smartphone in this way.

Importantly, operating at a low voltage is good for a battery's lifespan, increasing the number of available charging cycles before you'll start to see a major reduction in capacity. Roughly speaking, every 0.1V decrease in cell voltage doubles the cycle life, according to Battery University. Therefore, charging up your phone in that 30 to 80 percent range keeps the voltage lower and prolongs the battery lifespan.

Lower battery voltages help prolong capacity over time. Green: lower voltage charging for first ~65%. Yellow: Start of constant voltage. Red: Long period of high voltage charging for last 15%. Furthermore, the "depth-of-discharge" has a similar effect on the total discharge cycles before battery capacity drops off. This refers to the amount the battery used up in between charges. Smaller discharges, in the region of 60 percent rather than 100 percent between refueling can double the lifespan of your battery, and only using 20 percent can double the life again. Using up just 20 percent of your battery between charges isn't going to be practical for most people, but topping up when you've used about half will see a notable improvement in your battery life over the long term, especially if you avoid charging up to full each time too. The bottom line is that small regular top-ups are much better for Li-ion batteries than long full charge cycles

Heat is the enemy of long battery life

Along with all of the above, temperature is an equally key contributor to battery longevity. Just like high voltages, high temperatures stress the battery and make it lose capacity far more quickly than when kept at lower temperatures.
A cell kept between 25 - 30 degrees Celsius (77- 86 degrees Fahrenheit) should retain around 80 percent of its capacity after the first year even when cycling from empty to full charge. Battery capacity will be higher than this after a year if smaller periodic charging cycles are used. Raising the temperature to 40°C (104F) sees this fall to just 65 percent capacity after the first year, and a 60°C (140F) battery temperature will hit this marker in as little as three months. The ideal temperature to maximise battery cycle life is between 20°C and 50°C

Big phone batteries don't guarantee long battery life

Fast charging technologies are a contentious issue here, as the higher current and voltages can definitely lead to a hotter device while charging. Fast charging was never really envisioned for full- cycle charging though, instead, ifs a fast way to top up your phone quickly to get it back in your hands. Leaving your phone to quickly charge up for 15 to 20 minutes won't lead to major overheating problems, but certainly don't recommend using

Bringing this all together

Lithium-ion battery technology is well understood these days, but bad habits and myths still permeate public consciousness. While most of these habits won't severely negatively impact your phone's battery life in the medium term, the decline in removable phone batteries means we should take extra precautions to maximize our phone's battery life and cell longevity.

How to extend your Android's phone battery life

Broadly speaking, smaller regular charge cycles and keeping your phone cool are the key things to remember. Although I should point out that different phone batteries will always age slightly differently depending on how we treat them. Here's a TL;DR summary of the battery tips above:

What's the best way to charge your smartphone?

1. Avoid full cycle (zero-100 percent) and overnight charging. Instead, top-up your phone more regularly with partial charges.
2. Ending a charge at 80 percent is better for the battery than topping all the way up to 100 percent.
3. Use fast charging technologies sparingly and never overnight.
4. Heat is the battery killer. Don't cover your phone when charging and keep it out of hot places.
5. Turn your phone off when charging, or at least don't play games or watch videos to avoid mini- cycles.

Source: Battery University & Android authority