Wireless charging has been around for many years now. Google included it in the Nexus 4, Samsung with their Galaxy S6 family. Even Apple started including wireless charging capabilities since the launch of the iPhone X.
However, while the concept itself promises to be quite confortable and futuristic, the uptake of wireless chargers is still quite low. The main reason being cited is always the same: the slow charging speeds involved.
Today, OnePlus is changing that.
The fastest wireless charger in the market
The new OnePlus Warp Charge 30 Wireless is, by far, the single fastest wireless charger in the market. With a peak power of 30W, it is even faster than any wired charger for most smartphones! Google’s Pixel family supports up to 18W, while the iPhone can charge at up to 22W (and that’s using their separate USB-C charger, since their original one only provides 5W).
In fact, the maximum the wired Warp Charge supports on the new OnePlus 8 Pro is – you guessed it – 30W. Exactly the same as via wireless! This makes the new OnePlus Warp Charge 30 Wireless an extremely attractive option for anyone.
The company has confirmed that it will be able to power up the OnePlus 8 Pro from 1% to 50% in under 30 minutes. But how exactly has OnePlus achieved this feat of engineering?
The physics behind fast wireless charging
Regular wireless charging works by transmitting power using inductive coupling between two coils. However, there are certain physical limitations on how much power can be safely transferred via this method.
The Qi Standard, first released in 2008, is by far the most widely used technology in the industry. All Qi-compatible accessories can charge at a minimum of 5W, with some able to deliver 7.5 W, 10W and even 15W for certain fine-tuned devices (like the Samsung Galaxy S7 and above).
Regular Qi chargers achieve this by using a high voltage and a relatively low current. Physically, this represents the best way to minimise energy loss, which otherwise gets released in the form of heat. For example, the most powerful Qi wireless charger achieves 15W by using 9V/1.67A. A voltage of 9V is in fact the maximum that a smartphone’s internal circuitry can take as input. Only the 1.67A could potentially be increased, but this would drastically reduce the energy efficiency of the process, at the cost of creating vast amounts of heat, which would make this extremely dangerous.
A solution made in OnePlus
OnePlus is able to safely deliver 30W by combining two charge pumps with propietary warp charge circuitry, as explained by Evan Z., an employee from the Global Product Team at OnePlus.
The mechanism is as follows: first, the charger coil sends 20V/1.5A to the charge pump. This represents 30W, while the heat created is minimised due to the low amperage. Then, the first charge pump halves the voltage to 10V, while doubling the current to 3A. This gets sent to the second charge pump, which does the same, halving the voltage to 5V and doubling the current to 6A. This is exactly the same that gets sent via the wired Warp charger, and in fact the same propietary warp charge circuitry is employed to safely deliver it to the battery of the OnePlus 8 Pro.
According to OnePlus, the charge pumps employed ensure an energy efficiency of 97%.
OnePlus Warp Charge 30 Wireless Charger: the full details
The charger itself is a stand charger with an integrated power cord (which cannot be removed). It also has a built-in internal fan to prevent overheating.
While the fan is not too loud, OnePlus has enabled by default a “slow” charging mode during the hours of 23:00 and 07:00 (can be easily customized via software). This means that the fan will not be needed as much during the night, helping to minimise any potential sound during the night.
In-built safety protection
OnePlus has also included a series of safety protection rules to prevent any potential overheating, overcurrent or overvoltage in the sytem. If the phone starts getting too hot, or if a metallic object nearby makes alterations in the magnetic field, the charger will reduce its power to ensure a that succesful and safe charge takes place.
Only the OnePlus 8 Pro will be able to enjoy its full 30W juice. The OnePlus 8, unfortunately, will not be able to benefit from 30W wireless charging. However, OnePlus has made the Warp Charge 30 Wireless Charger fully Qi-compatible. This means that, apart from working with the OnePlus 8, it will alsobe able to charge any other phone that supports Qi wireless charging, although at the 5W standard rate.
OnePlus has surprised the market with this announcement. They always said that they wouldn’t launch a wireless charger until it could offer the same reliability and speeds as regular wired charging, and it today they have achieved that.
This launch adds more pressure onto competitors like Apple, who is yet to release their long-awaited AirPower wireless mat. Perhaps in late-2020?