A minor adjustment by Google has revealed the true nature of fast charging for mobile phones.

To "make money" from users, mobile phone manufacturers are coming up with more and more tricks. On August 20th local time, the annual Made by Google 2025 kicked off. As usual, the new flagship Pixel 10 series was officially unveiled. The integration of hardware and artificial intelligence (AI) technology became the highlight of Google's annual hardware press conference this time.

Besides the highly anticipated AI features, there is an interesting detail worth noting. Google claims that the "Battery Health Assistant" function of the Pixel 10 series will be forcibly enabled, and users cannot turn it off manually. It is reported that after the phone's charging cycle reaches 200 times, this function will gradually reduce the maximum battery voltage in stages until the recommended battery replacement point of 1000 charging cycles.

In short, the effect of the "Battery Health Assistant" function is to slow down the battery aging rate. However, as users use the Pixel 10 series, the phone's battery life and fast - charging ability will decline simultaneously. And what Google claims, that "it can charge up to 55% in about 30 minutes", will not take effect throughout the entire usage life cycle of this series of models.

Then the question arises. The "Battery Health Assistant" function does make the battery more durable, but it also has a negative impact on the user experience. So why does Google do this?

The AI features such as Magic Cue and Camera Coach of the Pixel 10 series are implemented based on on - device AI. Especially the "Pro Res Zoom" function introduced in the Pixel 10 Pro/Pro XL relies on the on - device large model to intelligently enhance the image and fill in details. Thus, without changing the hardware solution, it can achieve an ultra - high resolution zoom of up to 100 times.

Although the full integration of Gemini AI into the Pixel 10 series does make "mobile phone AI" more useful, relying on on - device AI comes at the cost of poor battery life. After all, calling Tensor G5 for AI calculations not only generates more heat but also has extremely high power consumption, which is a nightmare. Unfortunately, the battery of the Pixel series smartphones has always been a shortcoming.

Take the new version of the EPREL energy - efficiency label certification for electronic devices officially implemented by the EU this year as an example. It mandates that all smartphones launched in the EU must maintain at least 80% battery health after 800 charging cycles. However, the Pixel 10 series can only ensure at least 80% battery health after 1000 charging cycles. Under the same framework, the Samsung Galaxy S25 series can achieve up to 2000 battery cycles, and models from domestic manufacturers such as OPPO can reach 1600 cycles.

The so - called battery cycle refers to the process of a battery completing a full charge and discharge. For example, using the phone battery from 100% to 0% and then charging it back to 100% counts as one cycle. However, in actual use, the calculation of battery cycles is more flexible. Suppose you use 50% of the battery today and fully charge it, and then use another 50% the next day. The cumulative consumption of 100% of the battery also counts as one cycle.

Given that smartphones have become the "new organs" of modern people and it is common for people to be inseparable from their phones, assuming that users complete two full charge - discharge cycles per day, the battery of the Galaxy S25 series can last for 33 months before decaying to 80%. However, the Pixel 10 series may only last for 16 months, and users will clearly notice a significant drop in battery life.

What's more fatal is that due to Apple's previous experience, Google can't secretly "protect" the phone's battery.

Previously in 2017, a Reddit user claimed that after he replaced the battery of his iPhone 6S Plus himself, the phone's performance actually improved. As more and more iPhone 6/6S users reproduced this phenomenon, Apple had to admit at that time that "it did limit the performance of some older iPhone models. Limiting the peak performance of the processor can reduce energy consumption, thus preventing the old devices from automatically shutting down due to battery depletion."

Then, the conspiracy theory widely circulated among Apple fans, that "every year before the autumn new product press conference, Apple CEO Tim Cook presses a magic button on his desk, and all old models immediately start to slow down and lag", seems to have become a reality. This is the famous iPhone "battery gate" incident. Eventually, Apple paid a sky - high settlement of $500 million for its planned obsolescence operation.

In this way, quietly alleviating the decline in battery life by reducing the performance of user devices has become a dead end. What Google is doing now is equivalent to admitting that the battery life and fast - charging ability of the Pixel 10 series start to decline from the moment of activation, directly putting "planned obsolescence" on the table. In addition, prohibiting users from turning off the "Battery Health Assistant" function actually has an underlying meaning, that is, third - party batteries are likely to be useless because they probably don't have the function to reset the system's battery cycle count.

In fact, Google's forced activation of the "Battery Health Assistant" to cover up the inferior battery quality of the Pixel 10 series compared to its competitors has inadvertently revealed an unspoken rule in the mobile phone industry. That is, when manufacturers claim that a battery supports 1600 cycles, they often only mention that the battery can still have 80% of its capacity after reaching the specified cycle count, but never mention that the decrease in battery capacity will lead to a reduction in the activity of the positive and negative electrode materials, which in turn increases the internal resistance and makes the fast - charging protocols (such as PD/QC) unable to maintain the peak power.

Don't be deceived by the fancy promotion of fast - charging power by mobile phone manufacturers. Phrases like "fully charge an equivalent 4600mAh battery in 10 minutes" once made users worry that such high - power charging might damage the phone. Now Google's approach shows the truth of mobile phone fast - charging from the side. The so - called 90W, 120W, 150W, and 240W fast - charging actually have an "expiration date", and the more frequently the phone is used, the harder it is to maintain the fast - charging efficiency.

Yes, not only the phone battery is a consumable, but fast - charging is also the same.

This article is from the WeChat official account "3eLife" (ID: IT - 3eLife). The author is 3e Jun. It is published by 36Kr with permission.