What is Fast Charging?
One of the key factors that help us choose our mobile phones or electric cars and many other tech products that run on batteries. But what is fast charging and how does fast charging work? Let us look at this question, and also about other related topics to it, such as the fear of degradation of the battery, in mobile phones that charge faster.
History of fast charging
First mobile phones had very small batteries, usually below 1000mAh, and therefore, they did not take much time to get fully charged either. Moreover, the phones were rarely used for anything else other than calling and basic messaging, so the batteries lasted longer. But slowly as mobile phones became powerful, and the features became more popular, the batteries also became large, when it was about 2000-3000 mAh, the phones took a long time to charge, even longer than 2 hours in many cases.
This is when the manufacturers of mobile, started investing in fast charging technologies. Initially, Phones were charged at a rate of 5W(5v*1A). The first fast-charging phones were twice as fast, charging at the rate of 10W(5*2). but these features were pretty unnoticed until the first one plus phone came out with its 20W ‘Dash Charge’ in its One plus 3 Smartphone, which could charge the 3300mAh battery in less than an hour.
Since then, smartphone manufacturers have been constantly improving both the charging technology and software to enable faster and faster charging. since the one plus 3, we saw the rise of 30W, 45 W, 65 W and currently at a whopping 150W from Realme, which could charge the phone to full capacity from 0 to 100 in under 12 minutes. The first phone is equipped with Qualcomm Quick charge 5, the Legion 7 pro is roumerd to charge at a speed of 170W, and Oppo has demoed a 240W concept.
How does Fast Charging Work?
In order to understand how fast charging works, we should first know what is fast charging and how a lithium-ion battery works. When we charge the battery, we supply a current, say I at a specific voltage V, and the battery charges at the rate of (I*V) watts. the I and V are no longer constant and become lower as the charge of the battery is filled. so if you see a 20W charger from Apple, it supplies the phone with a 4A current at 5V. 20W is no longer considered fast charging, as even budget phones ship with 33W bricks in 2022.
1. Is Fast Charging bad for the battery?
Fast charging is achieved by pumping high current at high voltages to a space confined lithium-ion battery. This does pose many challenges for manufacturers, like overheating of the battery, overcharge etc. but luckily, they have found workarounds, and it is assuring to say that a modern 120W charger does less damage to the battery than a 20W charger to an iPhone, thanks to an array of precautions and innovations in recent years, like split charging (The battery is split into two parts and charged separately, in this case, at 60W), the introduction of graphene strips to spread out the heat, etc.
there are also many safety precautions to improve the life of your battery, like manufacturers disabling some portions of the batter (around 20) so as to work around the issue of exponential increase in degradation of battery at extreme ends(below 10% and above 90% as mentioned in “This is why you should never charge your battery to 100%.“. for example, the Redmi 11 hypercharge has an actual capacity of 5120mAh, but limits it to only 4600mAh, thus eliminating the risk of decay. So in effect, no, Fast charging is not bad for the battery If, it is implemented correctly.
2. Things you can do to further reduce battery degradation
- Do not charge and use your phone for heavy stuff
- Do not charge the phone in direct sunlight
- If possible, keep your charge between 15 and 85 %.
- Avoid using your phone in direct sunlight.
- Don’t charge the phone overnight.