Oppo came up with 125w fast charging: from 0 to 41% in 5 minutes, and a compact charger for iPhone

Yesterday, oppo released a new generation of flash charging technology, which increases the charging power of mobile phones to 125w, which is higher than that of most notebook computers.

The measured speed is also amazing: you can charge a 4000 MAH mobile phone battery from zero to 41% in five minutes, and charge the mobile phone in 20 minutes.

So is oppo a new technology safe and reliable? If you're an iPhone user, can you just watch? With these two questions in mind, let's take a look at what "black technologies" oppo has released this time.

Is 125w fast charging safe?

High charging speed is a good thing, but no one wants the mobile phone to be heated seriously or even explode when charging at high power.

How much electricity in 125w will be charged into the mobile phone, that is, how efficient is the charging? This is a key problem, because the power is either charged into the battery or lost as heat.

If the mobile phone is hot when charging, the user experience is very poor, and there are also security risks.

After all, oppo's fast charging power has reached 125w, and even if 10% of the energy is lost into heat, the heating can not be underestimated.

In order to improve the efficiency of power conversion, oppo official said: in the mobile phone, a parallel three charge pump scheme with conversion efficiency of up to 98% has been used.

The output 20V 6.25A power of the charger is converted into 10V 12.5A by three parallel charge pumps to enter the battery. Each charge pump only needs to convert about 42W of 20V 2.1a power, which effectively avoids the overload and overheating of the charge pump caused by large current.

In addition to the heating caused by the charging circuit, the battery will also generate heat during the charging process, which has a greater impact on the safety of mobile phones.

The heating of battery is mainly caused by internal resistance. The calorific value of the circuit is determined by the current and resistance, and the resistance is inversely proportional to the cross-sectional area and directly proportional to the length.

In the previous fast charging scheme, oppo adopted the scheme of parallel charging of two batteries and the charging pole ear in the middle. In this way, the distance of current flowing through the battery becomes shorter and the calorific value becomes smaller.

When the power is further improved, other technologies are needed to further reduce the resistance of the battery during charging.

Inside the cell phone lithium battery, the positive and negative electrodes are pasted together, and then rolled up like a roll cake to form a multi-layer structure. Generally, lithium batteries only have polar ears on one layer, and all current flows from this pair of polar ears to each layer of the battery.

The multipole lug technology makes the lug almost everywhere, and each layer of the cell has positive and negative electrodes, so the distance of charge flow to each layer is doubled, and the internal resistance of the battery is further reduced

Moreover, the multipole lug is equivalent to increasing the cross section of the wire, which can withstand more current, allowing up to 12.5A current input, effectively reducing the heating of the battery during charging.

All of the above are the preparation in advance of the fast charging scheme. In the process of practical application, there should be multiple measures for defense, and timely measures should be taken to avoid accidents when the mobile phone overheats.

Therefore, oppo adds 10 temperature sensors to the 125w fast charging battery, and the temperature sensors are set at the terminal lug and the connection of BTB power supply motherboard to monitor the charging situation in real time, providing much more temperature monitoring than before. The maximum temperature of the body during charging is not more than 40 ℃.

There is also the 65W wireless fast charging released yesterday. Oppo adds semiconductor refrigeration technology to the wireless charging board, which is similar to the cooling back clip of game mobile phone. It exports the heat from the back of the mobile phone to ensure that the temperature can be controlled within 40 ℃ during wireless charging.

What to do without oppo mobile phone

If there is no oppo mobile phone, will it not be able to enjoy the latest fast charging technology of oppo? No!

In addition to the fast charging of mobile phones, oppo also released two charging heads yesterday, enabling non oppo users to use the latest technology.

These two products support a variety of fast charging standard charging head, and the volume of the charging head is compressed to a very small level, and can even be easily put into the jeans pocket.

Generally speaking, the volume of high-power charger will be larger in order to insert more devices and ensure heat dissipation.

This time, the 65W biscuit charging head released by oppo is only the size of "Wangwang Xianbei". It adopts the current popular Gan switching power supply with high efficiency and low heating.

Why is it so small? Generally, after converting AC to DC, the charger will use electrolytic capacitor to store energy and stabilize voltage, but electrolytic capacitor occupies a large part of the volume. Oppo uses aviation grade clamping diode instead of electrolytic capacitor to further compress the volume of charging head.

According to the official data provided by oppo, "biscuit charger" has an energy density of 2.4 watts per cubic centimeter, which is extremely efficient, while the ordinary charger is only 0.6 watts per cubic centimeter.

Now people's electronic products are more and more, notebook computers, tablet computers, mobile phones, smart watches, Bluetooth headsets and so on, all need charging.

Although the charging interface has been gradually unified to usb-c, users can't take less chargers when they go out.

The main reason is that the fast charging standard is very confusing. Common standards include USB PD, QC of Qualcomm, FCP of Huawei and AFC of Samsung.
Each family can not be compatible with each other. If a charging head is used for B, B can only charge slowly. If you want to make every device enjoy fast charging, you need to carry different charging heads. This makes interface unification meaningless.
The oppo chip charging head supports not only 65W self charging protocol, but also 27W PD fast charging protocol and 18W QC fast charging protocol.

△ rapid charging of iPhone measured by oppo "biscuit charger"
So oppo released two charging heads that support a variety of fast charging standards, and compressed the volume of the charging head to a very small size.
The 27W PD charging power is still a little low for laptop computers, so oppo also has a charging head supporting 65W PD fast charging, which is enough to meet the charge of mainstream office books.