Someone finally said that the bigger the battery capacity, the better

Witty cat

2024-06-24 18:14Published in Chongqing Science and Technology Creators

In the second half of this year, one of the trends in the mobile phone market is that the battery is getting bigger and bigger. Not long ago, OnePlus showed off its latest glacier battery, which has a capacity of up to 6100mAh and will debut on the OnePlus Ace 3 Pro on June 27.

Earlier, vivo, Huawei, etc. have also launched several mobile phones with 6000mAh batteries, and it is expected that in the wave of new phones that will arrive in October, there will be a number of flagship phones equipped with large batteries of 6000mAh and above. Many people have concluded that range anxiety will be a thing of the past.

However, we also know that a larger battery capacity does not mean longer battery life, and some mobile phones with large batteries have the same battery life as mobile phones with smaller battery capacity, or even shorter. What is the reason?

In fact, on the one hand, this is inseparable from the manufacturer's battery life tuning optimization, and on the other hand, it is also related to battery energy.

Note that this is talking about battery energy, not the common battery capacity in mAh, what is the difference between the two and what is the relationship? A lot of people don't know.

Neglected mobile phone battery energy

For example, the battery capacity of the original Xiaomi mobile phone was 1930mAh, and the current Xiaomi 14 Pro is 4880mAh. The higher this number, the more "big" the phone battery.

But if you know a little bit about batteries, you will know that battery capacity and battery energy units are different, so capacity is not equal to energy. Battery energy refers to the stored energy, which is measured in watt-hours (wh). We often say that 1 kilowatt-hour of electricity is 1000Wh (1kWh).

So what is the relationship between battery energy and capacity? Here's a formula: battery energy = nominal capacity X nominal voltage. For example, the nominal typical capacity of the Honor Magic6 Pro is 5600mAh, the nominal voltage is 3.86V, and its battery energy is about 21.62Wh.

This means that the energy stored in the battery will vary depending on the operating voltage of the battery with the same capacity. The most typical example is the vivo X100 Ultra, which has a battery capacity and voltage in small print at the bottom of the product detail page: "This product is designed with a single cell: typical capacity: 5500 mAh (3.80V), typical energy: 20.90 Wh". The vivo X100 Pro "typical capacity: 2700mAh (7.78V), equivalent to 5400mAh (3.89V), typical energy: 21.01Wh".

Do you see it? The vivo X100 Ultra has a battery capacity of 5500mAh, and the X100 Pro is 5400mAh, but because the nominal voltage is 3.80V, which is smaller than the X100 Pro's 3.89V, the X100 Ultra with a larger battery capacity has less battery energy than the X100 Pro.

vivo X100 Ultra

vivo X100 Pro

The bigger difference in battery energy is also between the phone and the laptop. The common battery voltage of mobile phones is about 3.7V, and the energy of a 5600mAh battery is 20.72Wh, while the battery voltage of a laptop is 11.1V, and the 5600mAh battery also has an energy of 62.16Wh, which is 3 times that of a mobile phone battery.

If you understand this, you can understand why the 20,000mAh power bank you bought ran out of power after charging the mobile phone twice.

This is precisely because the nominal voltage of the 20000mAh power bank is 3.7V, the rated battery energy is 74Wh, and the output voltage when charging the mobile phone is at least 5V, and the rated capacity calculated at the output voltage of 5V is 12000mAh, which can only fully charge the X100 Ultra 2 times.

Battery energy density is a big game

So why don't mobile phone batteries use Wh to mark the energy value, but use mAh to mark the capacity? This is because in the actual charging and discharging process, the voltage is constantly changing, when the battery energy is sufficient, the battery output voltage may be higher than 4V, and when the battery energy is low, the voltage may only be 3V, which cannot be accurately calculated. The nominal voltage mentioned above usually refers only to the discharge cut-off voltage.

In addition, the discharge cut-off voltage of the mobile phone is about 3.7V-3.8V, and the value is not much different.

However, in the second half of this year, the 6000mAh battery popularization war is not so much a competition for mobile phone battery capacity, but essentially a battery energy density competition.

I believe you have found that with the maturity of silicon anode battery technology, the word battery energy density has been mentioned more and more. Because the energy density of the battery determines the amount of electricity stored in the unit volume, the higher the energy density in the same volume, the greater the battery power.

The energy density of mobile phone battery is not a new term, but due to technical reasons, mobile phone manufacturers have not popularized it too much. In the traditional graphite anode battery, the energy density of the battery is around 670wh/L, which has always been a bottleneck, but after the breakthrough in silicon carbon anode material technology, the energy density of the battery has been continuously improved at a higher specific capacity.

At the OnePlus Glacier battery press conference, its energy density of 763Wh/L was mentioned. But this value is not the highest, Xiaomi GSR battery advertises the highest energy density of 779Wh/L; In March, the vivo X Fold 3 series uses leading second-generation silicon, and the energy density has also reached 780Wh/L. Subsequently, on the vivo S19 series, the energy density is as high as 809Wh/L, which is also the industry's first mobile phone with an energy density of more than 800Wh/L, which can be called a milestone breakthrough.

However, this record is about to be broken, Motorola officially announced that it will hold a new product launch conference on June 25, the new Moto Razr series will be equipped with Lenovo's self-developed high-voltage silicon carbon anode "Xinghai battery", its energy density reaches 822Wh/L.

Battery technology is still waiting for change

It is foreseeable that the continuous increase in battery energy density will make the ultra-large batteries of 6000mAh and above popularized this year. For the mobile phone space, without increasing the volume of the body, it is obviously better to increase the battery life by increasing the battery energy density.

Battery life is an important reference for consumers to choose mobile phones, and it is the core competition point of major mobile phone manufacturers. This year, vivo took the lead in promoting 6000mAh batteries in new phones in various price segments, including vivo Y200 series, vivo S19 series, iQOO Z9 series, etc. Its official DOU battery life has reached 2 days. When OnePlus released the glacier battery, it also announced that the OnePlus Ace3 Pro can have a DOU battery life of up to 2 days.

It can be asserted that after vivo and OnePlus, the follow-up of Honor, Xiaomi, etc. will also be a natural thing. There will be more mobile phone brands to launch mobile phones with "DOU battery life of 2 days", because everyone has already used the same silicon carbon anode battery technology, and the energy density is comparable.

Whether it is Jinsha River battery, Blue Ocean battery, Qinghai Lake battery, glacier battery...... Or the future XXX battery, the batteries of various major mobile phone manufacturers have not left the industrial chain, and they have carried out joint research and development of mobile phone batteries with Ningde New Energy (ATL) and launched their own battery brands. This is like a customized version of the processor jointly developed by mobile phone manufacturers and chip manufacturers - it has its own characteristics, but does not affect the open supply of the public version. It is only a matter of time before other mobile phone manufacturers will implement the technology.

The fierce competition in the mobile phone market requires other mobile phone manufacturers to keep up quickly, otherwise there is a risk of losing market share. But what we have been waiting for a long time is the real change in mobile phone battery technology, maybe solid-state batteries will be an answer, when will this come?

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