The Problem With Fast Charging
By: Aman'S L'Écriture
Tags: Science, Tech, Electronics, Technology, Blog

In this day and age we have USB type-C which allows your phone to charge at an immense rate, but, that is not the whole truth. Tech expert Aman here is going to explain to you the problem with fast charging.

We see companies these days showing off about how fast their new smartphone can charge. But what they don’t tell you is that faster charging doesn’t come without a consequence.

So very quickly, the way your battery works is with two poles, a negative and a positive.

Source: Arun Maini

At the negative end, you have a lot of free electrons and at the positive, you have less. So naturally, those electrons just want to flow from the negative end to the positive end.

Source: Arun Maini

And along the way, they can power whatever device you put in their path.

Source: Arun Maini

Once they have all flowed over, your battery is dead. That’s where charging comes in, we can use electricity to push electrons back to the negative side creating that difference again.

Source: Arun Maini

So in reality, all fast charging is doing is pushing those electrons back faster, however, there are some problems with this. For starters, it means that in any amount of given space, you get less battery capacity. In every battery between the positive and negative pole, there is a separator to make sure that the electrons don’t just go from one side to another.

Source: Arun Maini

This allows the electrons to flow through the circuit that you want it to and charge your smartphone. But, the faster you want to charge your battery, the thicker the separator has to be to maintain stability.

Source: Arun Maini

And therefore the actual amount of usable battery you have falls. If you want to take it a step further and charge ultra fast like a lot of these new phones that are coming out, then you have to split the battery in two.

Source: OnePlus, OnePlus 8T

As you can see, this wastes more space. This is why you will never see ultra fast charging unless it is on a huge phone because it takes up too much space.

Another problem is that faster-charging causes faster electron movement and this causes heat and heat is harmful to batteries

Source: Me

Heat slowly and subtly changes a battery’s structure which will make its ability to hold charge fall over time. As a very rough estimate, even if you kept your battery at 30 degrees celsius, you could expect to lose over 20% of your battery capacity over a year. And if you kept it at 40 degrees celsius, you could lose something like 40%. This is why it is recommended to leave your phone alone whilst it is charging.

Source: digitalinformationworld.com

Your phone will already be warm from the charging, using it is just going to add on to that.

You might have seen gaming phones position the charging port so you can game and charge, I would not recommend it.

Source: ROG Global

The only exception would be though is if you are going to use bypass charging which basically forces your charger to power the components of your phone directly and not touch the battery. So your battery percentage wouldn’t go up, nor would it go down.

So you remember how when the battery’s full we’ve basically pushed all of those electrons so that they’re sitting in the negative pole and when your battery’s empty how they all be sitting in the positive pole.

Source: Arun Maini

Well because of this, both 100% and 0% are actually the two most imbalanced and high-pressure states to leave your battery in.

Source: Arun Maini

In an ideal world, you would constantly keep your battery at 50% where the free electrons are evenly distributed between both the negative and the positive pole.

Source: Arun Maini

You might notice that when you buy a phone and you power it on for the first time, the battery is already sitting at around 50%.

Source: Arun Maini

The company you bought it from will do this because they know that their phones may sit on shelves for a long time so they keep it at 50% to allow the least battery degradation.

This brings me on to the third issue. The more powerful fast charging becomes, the more you’ll notice diminishing returns. Have you noticed how whenever manufacturers quote how fast their charges are, they'll always use the starting figure how “fast can it charge the first 50 for example”.

Source: Arun Maini

Well that’s because the wattage you get given is not actually the wattage that your phone will constantly be charging at, it’s just the maximum it can reach and it'll reach that maximum somewhere during that early part of charging.

Source: Oppo

As your battery starts to get full no matter how powerful your early charging is, you have to drastically slow down to protect the battery’s health and as a result, a 60-watt charger is not twice as fast as a 30-watt charger and a 120-watt charger is not even close to twice as fast as a 60-watt charger.

So fast charging does mean that you're going to get less battery as you use your phone and this is why some companies are integrating the option to slow charge and even using it as a marketing feature. It sounds crazy but hopefully, this makes sense.

Source: ASUS

You could say that this is the reason it took Apple so long to switch away from giving people the tiny little five-watt charging bricks. Obviously providing the 5-watt charger in the box will make them more money because they can then sell fast chargers separately but they also probably figured that because most of their users were fine, they didn’t really complain about the existing charging speeds. If they raised it all, it was really going to do is reduce the longevity of their phone.

Because Apple makes so much money on software and services, they want people’s iPhones, which are the access point to that content, to last as long as possible.

Source: Apple

This is why they provide software updates for five years solid on every model, it's why they even tried to slow down older iPhones to preserve their battery life. Apple wants its phones to last a long time. That’s part of the reason why they haven’t introduced 65-watt fast charging.

Source: Apple

I talk about fast charging and the problems with it, but I do want to stress that it's not as bad as it seems. For starters, people seem to have this idea that slow charging is good for your battery, I wish it was true but no, no matter how careful you charge your phone, your battery will not be as it once was when you first got it.

Another point is that we now have a solution to over-night charging. Companies are introducing smart-charging bricks so that your charger can communicate with your phone and will have the option to only charge at a certain percentage when you want it to. For example, you could set your iPhone to charge throughout the night at 50% but then carry on charging to 100% when it's time to wake up.

I would say that in 2020, you would get a 30-watt charger for maximum efficiency, to maintain a healthy battery for a long span of time which can charge at a decent speed.