Shulou(Shulou.com)11/24 Report--

The phone still has 20% power left, sent two voice messages, and automatically turned it off. Is it possible that my phone can only send ten voice messages when it is fully charged?

The electric car shows that it still has 10% power left, rubbed less than 100 meters, and directly broke down. Is it possible that my car is only one kilometer full of electricity?

Electricity anxiety is like a midlife crisis. The more anxious you look at it, the more you want to see it.

In Apple's latest iOS 16, the iPhone percentage display, which has been gone for five years, is back. Today's updated official version of iOS 16.1 is optimized so that the battery icon changes synchronously as the battery value decreases. (previously, most of the space at the top was squeezed by the bangs screen design. If you want to know how much power is left, you can only check it in the control center by dropping down. )

The percentage hanging from the top of a mobile phone is like the countdown to a ticking time bomb (before update). For such a "return", many users shout "immoral"-the percentage hanging from the top of the phone, just like the countdown to a ticking time bomb, with its own brain tonic sound effect, always reminding you that it is time to recharge.

IOS 16.1 battery icon will also change synchronously, the full screen iPhone has supported the percentage display (updated). The screenshot of the picture source phone, which makes you anxious, is called SoC (State of Charge), which represents the ratio of the remaining capacity of the battery to the actual capacity. The amount of electricity left in a mobile phone (or electric car) cannot be measured directly, but can be estimated by measuring voltage and current.

So the remaining power of the battery is on its own?

The battery shows that it is a "hoax". Usually, the "fully charged" state displayed on the phone is not that the battery really cannot be charged-the manufacturer will define the charging cut-off voltage and discharge cut-off voltage for the battery: a common situation is that 1% of the electricity can last a long time, which may be because the engineer wants you to charge as soon as possible so that the battery will not be depleted and damage the battery.

There are a variety of measurement methods to "mask" the SoC value. Commonly used, such as the Coulomb meter (also known as the ampere-hour integration method)-statistics of the current in the process of use. To put it simply, when a metering chip is installed in the battery, different currents produce different pressure differentials. By integrating the changing current and time, the chip can get the amount of electricity that the user uses, and then the remaining power can be obtained.

The disadvantage of this measurement method is that it is an open-loop estimation system and does not have the ability to correct the initial value error and the ability to adjust the error caused by noise and measurement deviation.

Another common method of Battery University is voltage testing, which determines the change of electricity quantity by measuring the voltage of the battery. At a certain temperature, there is an one-to-one correspondence between SoC and open-circuit voltage (OCV). However, because the acquisition of open-circuit voltage often takes a long time to rest, it is difficult to carry out on-line estimation of open-circuit voltage.

The corresponding change of voltage and capacity at different temperatures is nonlinear. The OCV-SoC curve of Richtek Technology such as lithium iron phosphate battery is "nonlinear". In the illustrated range, even if the SoC changes in a large range, the numerical change reflected in the OCV is very small.

OCV-SoC curve of lithium iron phosphate battery? picture source reference 4 different measurement methods have their own advantages and disadvantages, and the common feature is that they all have errors. Manufacturers are also studying to establish a more accurate electricity estimation model through optimization algorithms (such as neural network, Kalman filter, fuzzy algorithm, etc.). For example, in the Coulomb method, the initial value needs to be calibrated with the Kalman filter method; in the open-circuit voltage method, the dynamic balance voltage is established based on historical data, and then applied to the real-time estimation of SoC.

What will happen if you are not allowed to do so? For example, the initial example shows that the battery is still 10% left, but when you click on app, the phone will not be powered off-perhaps because the battery is aging, and the SoC estimate is not good enough to predict the decay of the battery.

The inaccurate display of electricity has aggravated people's "power anxiety". For this reason, high-capacity batteries have once become an important selling point for smartphones, and mobile phone manufacturers are crazy about developing fast charging technology like an arms race. It's just that various measures have not completely cured people's heart disease.

Manufacturer anxiety, user anxiety, hardware anxiety, software anxiety, screen display and communication module are the most key factors that affect smartphone power consumption.

NICTA (Australia's National Institute for Information and Communication Technology Research) released a report in 2010 that in the era of functional phones, mobile phones have a small screen, not to mention the pursuit of high refresh rate, high resolution, wide color gamut and other features. Most of the functional aircraft can achieve a few days of service life, and some models with long range as the selling point can last for several months. In 2010, Philips released a Xenium X513 with a battery capacity of only 2000mAh, but 60 days of standby time and 20 hours of talk.

From another perspective, it is the battery that shapes the appearance of our mobile phones. In 1973, Motorola released the DynaTAC 8000X, also known as the "mobile phone", because half of its size and weight were occupied by batteries. The battery compartment composed of 6 cylindrical Ni-CD batteries was charged for 10 hours and talked for 35 minutes.

Martin Cooper, the father of mobile phones, holds the DynaTAC 8000X. The advent of TechWorld.hu Ni-MH battery technology has changed people's impression of mobile phones as "bricks". In 1996, Motorola's flip phone "StarTAC" was the lightest and smallest phone on the market at that time, with only 88g.

In the Wikipedia era, even if a battery does not last long, it can be "extended" by changing the battery-just like some new energy vehicles.

Until later, the emergence of iPhone brought the all-in-one fuselage, which has now become the mainstream, and also took away the convenience of "changing batteries". The size of the battery becomes larger and larger with the area of the screen. To this day, someone has taken apart the interior of iPhone 14 and found that batteries account for nearly 1/3 (up to half on iPhone 5).

Inside iPhone 14, there are many models with "big battery" as the selling point in the history of iFixit smartphone development. The Golden M5, released in 2015, has a 6020mAh battery that lasts 49 days on standby and can talk for 71 hours, at the cost of a thick and heavy fuselage (thick 8.5mm, 214g).

Other folk geeks are keen to explore solutions to "save power" through software optimization, among which Android users are the most representative.

At first, the hardware specification of Android is not high, single-core CPU,256M or 512m running memory, the system runs slowly and stutters. There are various root tutorials circulating on the forum. Many third-party ROM's UI is very exquisite, but users are more likely to uninstall the system's preinstalled applications, free up storage space, speed up the system and save power.

Articles such as "teach developers how to make a power-saving Android ROM" can also be found. The first geeks of the mobile Internet era managed the background by root the phone, installing the Xposed framework, and using software such as "green daemon" to prevent apps from waking up automatically when the screen was locked. After such "extreme training", the better endurance ability can reach about three or four days.

Green Guardian Application Interface (Google Play2010) A year ago, people who had just become popular with smartphones were most fond of discussing and spreading all kinds of "province electricity metaphysics" on the Internet: turning off Bluetooth, Wi-Fi,GPS positioning, actively cleaning the background, and even reducing the brightness of their phones, using dark wallpaper.

Android does not add the official power-saving mode until it is updated 5.0, which will degrade performance and delay automatic updates of some programs.

Phandroid Apple's power-saving mode starts with iOS 9: it activates automatically when the power of the device is less than 20%, increases the battery life by shutting down power sources such as background applications and location services, and automatically shuts down when the power of the device exceeds 80%.

To this day, some people still keep the habit of clearing the background and turning off Bluetooth, even though these measures have little effect on extending the flight range. According to a simulation test by Android Authority, the difference in power consumption between Bluetooth on and off during a day of use is only 1.8%.

Electricity anxiety: mentality problem or technical problem? While smartphones are becoming more mature in managing background software, the energy density of lithium batteries is getting higher and higher, and the power consumption of mobile phone chips is getting lower and lower, why is the curse of "one-day battery life" still there?

That's because although technology is improving, requirements and usage habits are changing as well.

Affected by the trend of large screen and thinning, mainstream smartphones seldom take "big battery" as the selling point. Fast charging has become the mainstream solution to power anxiety. "charging for 5 minutes and talking for 2 hours" was once a marketing paradigm. Now the ceiling is iQOO 10 Pro, charging specifications up to 200W and 10 minutes full of 4700mAh batteries.

IQOO screenshot iQOO official since the battery capacity is no longer difficult to increase, then increase its "resurrection times", when charging does not take much time, or even can be ignored, the anxiety caused by low power will be much less.

Reduction is not completely eliminated. At present, various fast charging protocols are complicated. In addition to public PD and QC fast charging, there are also private protocols such as OPPO's VOOC and vivo's FlashCharge, which require high adaptation of charging heads and wires. In addition to the original charging kit, many people will not match a few more sets to cover the whole scene. The price of a good third-party gallium nitride charger is more than 100 yuan, which is an extra cost.

Gallium Nitride Charger (photo source JD.com screenshot) the "mentality problem" of electricity anxiety ultimately depends on the development of battery technology. Battery technology is an extremely complex problem, which can not be solved by increasing energy density only by considering various factors such as battery life, safety, efficiency, cost and so on.

The essence of battery charge and discharge is the directional movement of ions between positive and negative electrodes, which is consumed when it reacts with the substances in the electrolyte (and will be affected by temperature). The moment the battery is made, its life is decreasing, and even if it is not used, it also has wear and tear. Everyone's mobile phone habits are different, which will also affect the actual speed of power consumption.

At present, with the combination of fast charging technology and power-saving mode, there is almost no need for us to pursue long life on the premise of sacrificing experience. It is only after learning the truth that we know that those worries in the past have been "mispaid" after all.

reference

[1] https://www.macrumors.com/2022/09/14/ios-16-1-battery-percentage-iphone-13-mini/

[2] https://www.ifanr.com/app/668211

[3] https://zhuanlan.zhihu.com/p/108788053

[4] https://esst.cip.com.cn/article/2021/2095-4239/2095-4239-2021-10-3-1127.shtml

This article comes from the official account of Wechat: fruit Shell (ID:Guokr42), author: Liu Diu Editor: Shen Zhihan

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.