The batteries of mobile phones are manufactured from lithium-ion electrolytes, and they are meant to last for about 3 years, which makes them far better than the older Nickel-based mobile phone batteries in terms of lifespan.
What defines battery life?
The battery life of a phone is limited, as we all are painfully aware; and it can be defined as the duration of which a fully charged phone battery will last before it is fully discharged to 0%. Battery life is a measure of battery performance and longevity, which can be quantified in several ways: the smartphone’s runtime on a full charge or the number of charge cycles until the end of its useful life. Normally, batteries are designed to meet up to the energy consumption of the phones.
Before we get to the main question “How often should I charge my phone to prolong battery life?” let’s get to know more about how phone battery works.
How does Phone battery work?
These days, the most commonly used battery is the lithium-ion (or Li-ion)—a type of rechargeable battery in which the lithium ions in its electrolyte undergo both forward and reverse reactions. During discharge, the ions will move from the negative electrode toward the positive electrode, and vice versa when the battery is charging. The charging procedure for Li-ion phone batteries is always in three stages:
- Constant Current Stage (~0%-80%): At this stage, the charger applies a constant current to the battery at a steadily increasing voltage until the voltage limit per cell is reached.
- Saturation Stage (~80%-100%): The charger reduces the charging current while the phone battery cell’s State of Charge (SoC) are brought to the same level. Here, the charger applies a voltage equal to the maximum cell voltage times the number of cells in series, as the current gradually declines towards 0.
- Ready Stage (100%): The battery terminates the charging where it stops accepting current from the charger.
- Standby Stage (<100%): At this phase, the recharge process is triggered to make sure the battery capacity is at 100%.
Now, to the main question
At what percentage should I always recharge my phone battery?
Modern phones have inbuilt power management application system, and they typically have a recharge reminder (sounds familiar, right?). Take Samsung and Apple’s devices, for example—they always alert their users to recharge their phones once the batteries hit the 20% mark. And this is the lower boundary limit when it comes to maximizing battery health; ensuring your phone battery doesn’t drop below 20% (or below the battery management app’s alert level) is key to improving battery life before it exceeds the manufacturer’s rated charge cycle. Generally, the charge cycle for most phone batteries is between 500 – 1500 cycles.
Good news is, most batteries nowadays are equipped with smart control circuits, which control the charging procedure. But that isn’t to say it’s all that’s ever needed to maximize your battery life. To further extend your battery life, remember the golden 20% – 80% rule.
That is, always (if possible) keep the battery level between 20% – 80% for prolonged battery life. Reason being that keeping your Li-ion battery at above 80% battery level stresses it and hence, degrades its lifespan. But understandably, to adopt such a habit is a tad bit inconvenient; not everyone can afford the time off daily to “micromanage” their charging.
That said though, all hope is not lost. The next battery saving strategy you can adopt balances both convenience and battery health: turning off the charger after the battery is full. Although not as effective as the 20% – 80% method, it still helps save battery life. Because by continually tuning in your phone to the charger past 100% level, your battery will periodically recharge to top up once the battery level drops. And this subjects your battery to more stress and consequently, more degradation.
To wrap things up, if you are looking to really maximize your battery life, keep your battery charged between 20 – 80% level. Or, if it’s too troublesome an effort for you, just power off your charger after your battery level is full. If that too, is troubling for you, you can get an auto disconnect charging cable to do the job for you.