Have you ever wondered why your smartphone battery always runs out well before it reaches the dreaded zero percent mark?
In other words, why does your smartphone die when your battery still has some juice left in it.
To answer that question let’s make a Pokemon Go analogy.
Suppose you’re about to catch a Dragonite and you notice that your phone battery is hovering around 5 percent mark. You think to yourself that you’ll be able to throw enough PokeBalls at the critter in order to catch it well before your battery runs out.
Suddenly your smartphone dies before you have a chance to throw your first PokeBall at Dragonite and the annoying critter runs away into oblivion.
You, on the other hand, are devastated. Why?
Well, first, because you are playing the most effort requiring, battery munching and time-consuming game of all time i.e Pokemon Go. It’s an augmented reality game too it sucks the life out of your battery even faster. In short, you need to stop.
The second reason for the misery you’re feeling right now is the lack of knowledge on how smartphone batteries work. But don’t worry, battery chemistry is more like black magic rather than science.
We’ll see why in a few moments.
Right now, the only thing you should know is that your phone is just a smartphone. That’s all it is. A smartphone.
It’s not the oracle. That is, your smartphone isn’t “smart” enough to figure out exactly how much charge is left in your smartphone battery.
The only way you can realistically do that is by physically inserting probes into the battery and using some sort of sensors to measure the charge.
And since the era of nickel-cadmium battery packs has long been over, your lithium-ion battery will probably explode if you insert anything into it. Yes, your lithium-ion battery is fundamentally a chemical bomb inside your smartphone that is used to generate electricity to power your phone.
Of course, there is the other side of the argument as well.
If a Lithium-ion battery can be considered to be a bomb then wouldn’t it be best if there was a way to insert a sensor into it so that the operator could be warned if there is something seriously wrong with the device?
To answer that we need to understand that the real reason why there are no sensors in modern batteries is because it is currently unclear what the sensor is supposed to measure.
If we take an example of electric cars where battery packs have sensors that count coulombs left in the battery and also a number of amps going in and out of the battery in order to report the state of the charge left in the battery.
Obviously, that technology would be extremely expensive if ported to a device as small as a smartphone.
So what does your smartphone do then, to figure out how much charge is left in the battery?
Well, it does maths.
Maths, some scientists believe, is your gateway to heaven. But since that can’t be proven (in all possibility is an absurd idea, to begin with), we’ll just stick to the math that your smartphone utilizes in order to calculate how much more screen time can it provide you with the remaining battery left.
It’s all a bit complicated but a guy by the name of Mark Smirniotis, who writes for Wirecutter, has done a fabulous job of explaining the concept.
Basically, he likens the smartphone battery to a barrel that you cannot see into.
Simple enough right?
He breaks down this mysterious behavior of your smartphone battery into three steps.
First, your device simply is incapable of reading a charge. Well it isn’t exactly incapable, it just experiences a lot of trouble while doing that.
Why? Not because your smartphone is dumb or something, but because batteries work in unpredictable ways.
Batteries from the inside are very sphinxlike. They are cryptic. Therefore, what your smartphone does is, it forecasts the charge left in the battery by using algorithms.
And as is the case with any mathematical formula, it works only till it doesn’t. What that means is that sometimes those algorithms are unable to predict accurately how much charge is actually left.
Second reason why it is very hard to properly to predict battery behavior is that any battery, whether it be in your smartphone or you car (or someday, as Elon Musk would say, in your house) or drone, loses its capacity to store charge as it gets older.
That further messes up any algorithm that might be used to predict how much charge is present in the battery at the current moment.
The third reason why batteries are so hard to work with is the process of crystallization.
That’s right. Crystals form on the walls of your battery from the inside. That further decreases its capacity to store energy as there simply isn’t enough space inside the battery as before.
All of these factors combine to wreak havoc on your battery meters and hence your smartphone is unable to show you the exact charge your battery has got left.
This results in your smartphone shutting down even though the battery meter on your screen shows about 10 percent points left.
The other thing a lot of people fail to take into account is the fact that not all batteries are made to stop working as soon as charge levels drop to zero percent.
Some manufacturers willingly program their smartphones to shut off with some juice left in the battery to guard against data corruption problems.
As people with a desktop computer would already know that a sudden shutdown of a smartphone or any computer device results in loss of data.
In order to protect data from being lost, some mobile phone manufacturing companies use internal clocks so that their smartphones shut down before the zero percent mark.
Normally, smartphones that come with non-removable battery come with this feature where the battery never goes to the zero mark and the smartphone shuts down before that point.
But there are other smartphones out there in the market that only shut down once the battery truly and absolutely reaches the zero level charge.
For those of us who have unknowingly let their laptop’s battery go to zero at some point in the past, it would be easier to visualize what happens when a battery is allowed to run its course and discharge completely.
Your device shuts down like in a second, which puts your data at risk. Not to mention the potential damage a sudden shutdown would cause to other hardware components.
You might think now that your battery meter estimates aren’t very accurate, to put it politely. And you would be right on that count. But remember, that the battery meter isn’t lying to you either.
If you count the number of factors your smartphone’s battery meter is supposed to take into account: such as voltage, current discharge, the performance of other components, temperature and battery age, it would be easier to understand why it messes up what gets shown on the screen as “battery left percentage”.
If you suspect that may be the case with your smartphone’s battery then you can pay head to the saying “the best predictor of future performance is past performance”.
In other words, the most reliable way (in the case mentioned above) to keep a track of how long will your smartphone’s battery will last today is to notice how long did it last yesterday.
What does this all mean then? Do you need to enroll in an electrical engineering course today or something?
All this means is that when your smartphone’s battery is running low and you’re busy doing some important work (like trying to evolve Pikachu to Raichu in Pokemon Go) then it is best to take the safe route.
Either shut down your device yourself or reach for a charger.