Most major phone versions today offer improved charging speeds. How do fast chargers work and how do they get faster? Find out here.
The rise of fast charging
Almost every newer flagship on the market offers a kind of quick charging. Manufacturers often throw out numbers like "80% in 30 minutes" or "a full charge in less than an hour" when marketing their latest devices.
The widespread introduction of fast charging is in many people a reaction to the increasing use of the phone. People need to charge their phones more than once a day. It is also a necessity. As phone sizes grow from year to year, they need larger batteries to keep up with the additional power consumption. Without quick charging, we would have to wait hours for our phones to charge.
In the simplest case, fast charging simply increases the number of watts (W) that are delivered to the battery of a telephone. A simple USB port sends 2.5 W to the connected device, and faster chargers increase that amount. Current generation devices generally have 1
For the end user, it is as easy as using a compatible quick charger for their phone. For manufacturers, however, this is not as easy as using a higher performance device.
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The quick charge process  Before we go any further, you should consider a simple formula. Power is calculated as the result of current (A or ampere) multiplied by voltage (V or volt). Electricity is the amount of electrical current transported, while voltage is the force that drives this current forward. Therefore charging with 3A / 5V delivers 15 W of power.
One thing you will notice is that many manufacturers are announcing their ability to perform a quick part load, e.g. B. 50-80% of the battery can be charged within half an hour. This is due to the way the rechargeable lithium-ion battery is powered in phones. If you have ever monitored how a battery is filled, you will find that the charging speed slows down over time.
The loading process can be divided into three parts. Further technical details can be found in the table "Figure 1: Charging levels of lithium ions" in this article from Battery University. In short, here's what it shows:
- Level 1 – Constant Current: The voltage rises toward its peak while the current remains constant at a high level. In this phase, a lot of electricity is quickly supplied to the device.
- Level 2 – Saturation: In this phase, the voltage has peaked and the current drops.
- Level 3 – trickle / covering: The battery is fully charged. In this phase, the energy will either be slowly introduced or, at regular intervals, be charged with a small amount of “refill” when the phone is using up the battery.
The amount of electricity and the length of each process depend on the fast charging standard. A standard is an established charging process that corresponds to a certain device, charger and a certain output power. Different manufacturers develop different charging standards that enable different outputs and charging times.
Quick Charging Standards
Here are the different quick charging standards implemented in mobile phones:
- USB power supply: Each mobile phone has a charging cable that uses USB. Even the Lightning cables for Apple's iPhones have a USB port on the other end. USB 2.0, a common specification for two decades, has a maximum output of 2.5 W. Since USB connections have to deliver more power, the USB-PD standard was created. USB-PD has a maximum power of 100 W and is used for a wide range of devices, including most flagship cell phones. All USB 4 devices will be equipped with USB PD technology, which will hopefully contribute to standardization.
- Qualcomm Fast Charge: Qualcomm is the most widely used chipset for flagship Android devices, and the latest processors are compatible with their proprietary fast charge standard. The latest Quick Charge 4+ has a maximum output of 100 W.
- Samsung Adaptive Fast Charging: This standard is used by Samsung devices, especially their Galaxy product ranges. This standard has a maximum output power of 18 W and automatically changes the charging speed to preserve the life of the battery.
- OnePlus Warp Charging: OnePlus uses the proprietary Warp Charging standard, which charges devices up to 30 W. Instead of increasing the voltage as with most other standards, unlike other options in this list, 30W charging is also available at full speed.
- Oppo Super VOOC charging: Oppo uses a proprietary standard that charges its devices up to 50 W.  Most companies that do not have their own charging technology use USB-PD or Qualcomm Quick Charge or adapt them to their specific device. Companies like Apple, LG, Samsung and Google use these standards for their flagship phones.
Most of these solutions increase the charging speed by increasing the voltage of their adapters. The outliers are Oppo and OnePlus solutions, which significantly increase the current and not the voltage. Fast charging with these devices requires the use of their proprietary cables.
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The future of charging
Charging technology is getting better and better, as manufacturers continue to increase charging speeds. Over the next few years, more companies will experiment with charging technology and new standards will emerge in the industry. However, it is likely that most of these standards will continue to use USB-PD as the backbone.
There is also the advent of wireless fast charging. Wirelessly transmitting large amounts of electricity can be dangerous without proper heat management. Wireless charging is still significantly slower than wired as technology companies are still figuring out how to deal with the heat. For this reason, companies like OnePlus have released 30W wireless charges with large fans to ensure adequate airflow.
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