Mazer MagAir31 on hand: 17mm thin 10,000 mAh backup battery, Qi2.2 wireless charging, USB-C 45W

Mazer MagAir31 has a capacity of 10,000 mAh, 17 mm thin body, supports Qi2.2 wireless charging up to 25W and fast charging via USB-C port with 45W capacity. Mazer MagAir31 focuses on three main factors including compact design, high-power wireless charging and 45W wired charging capability. With a capacity of 10,000 mAh but a body only about 17 mm thick, the product is aimed at daily carrying needs, especially for iPhone users and Qi2.2-enabled devices.

Compact design compared to 10,000 mAh capacity

When looking at the 10,000 mAh capacity and 45W maximum USB-C capacity, I initially thought the MagAir31 would be quite big and thick. However, in reality the product has a thickness of about 17 mm and a weight of just over 200 grams, relatively compact for a battery with both large capacity and integrated wireless charging.

The frame is made of metal, surrounding the battery body to increase sturdiness. The two surfaces use rough plastic, somewhat limiting fingerprints during use. The wireless charging magnet ring area is arranged similarly to other MagSafe/Qi2.2 backup batteries. When attached to the back of the iPhone, the battery size is quite suitable and does not take up too much space.

To prioritize size and weight, MagAir31 does not integrate a stand. This is a suitable trade-off for people who mainly need a simple battery that can be attached directly to the phone or placed lying down while charging. When charging and using, the total weight of the phone and battery will be around 450 grams depending on the device. It cannot be called light, but it is still within the level that can be used for short periods of time and in return the user has a backup battery capacity of 10,000 mAh.

Having CCC certification is convenient when moving through China

On the product and packaging there is information related to safety standards. The detail I'm interested in is the CCC (China Compulsory Certification) certification mark that appears directly on the battery body.

This is a notable factor for people who frequently travel by air in China, in the context that the country has increased requirements for spare batteries carried on planes. The fact that certification information is displayed right on the product makes the inspection process at the airport more convenient.

Full charge time is less than 2 hours 30 minutes

To test the MagAir31's ability to recharge, I used a power meter throughout the entire process. With a charger of appropriate capacity, the battery takes about 2 hours and 21 minutes to charge from empty to full.

The meter recorded a total of approximately 40.54 Wh of input power. Meanwhile, the battery's nominal energy capacity is about 38.5 Wh. If we compare these two parameters, the difference is about 2.04 Wh, corresponding to a calculation efficiency of nearly 95%.

This figure shows that recharging the MagAir31 has a relatively low loss. The difference in energy is mainly consumed in the voltage conversion process, the operation of the power management circuit, the resistance of the battery cell, the conductor and finally converted into heat. The average input power during the entire process is about 17.25W. The actual capacity is not constant but is higher in the early stages, then gradually decreases as the battery approaches 100%. It should be noted that the level of nearly 95% here is calculated based on the power measured at the input and the nominal energy capacity of the battery, so it should not be understood that 95% of the power from the charger is stored directly into the cell. However, the results still show that MagAir31 does not consume too much energy during recharging.

Wireless charging efficiency reaches about 78.6%

I tried MagAir31 with iPhone 18 Pro Max to see the actual wireless charging speed. The test starts when the iPhone has 1% battery left and the MagAir31 is at 100%. In the first 10 minutes, iPhone increased from 1% to 18%. After 30 minutes, the machine reached 41%, equivalent to an increase of 40 percentage points. By the 40th minute, the iPhone reached 53% and after exactly one hour it reached 72%.

The 80% mark was completed in about 70 minutes, meaning the iPhone increased by 79 percentage points in just over an hour of charging. At this time, MagAir31 has 35% battery left, equivalent to 65% capacity used. This speed shows that most of the charging process is quite fast in the range of 1–80%. After the 80% mark, the iPhone will actively reduce receiving power to control temperature and protect the battery, so the last 20% usually takes longer. If converted by nominal energy capacity, 79% of iPhone 18 Pro Max's battery is equivalent to about 16.64 Wh, while 65% of MagAir31 capacity is equivalent to about 25.03 Wh. The cumulative conversion efficiency calculated in this way is about 66.5%.

To have more basis for performance evaluation, I also tried a complete cycle with iPhone 15 Plus. When charging from 0% to 100%, the phone receives about 16.95 Wh, while MagAir31 consumes about 21.56 Wh, corresponding to a conversion efficiency of about 78.6%. As such, actual performance will vary depending on the device, charging capacity, temperature and stage of the cycle. The iPhone 15 Plus test shows the loss of MagAir31 in a complete cycle, while the iPhone 18 Pro Max more clearly demonstrates the ability to prioritize speed: the device increases from 1% to 41% after 30 minutes and reaches 80% after about 70 minutes. Wireless charging performance is also directly related to thermal control. The higher the temperature, the more the system tends to lower power to protect both the phone and the backup battery.

During testing, the highest MagAir31 surface temperature I measured with a heat gun was about 36–37°C. This is the level of heat that can be clearly felt when held but is not too hot. When switching to wired charging at high power, the metal rim may heat up more clearly. This is understandable because the power circuit must handle large capacity in a relatively thin battery body.

USB-C 45W can be used with many devices

Besides wireless charging, the USB-C port is what makes MagAir31 more flexible in practical use. The maximum output power of 45W is enough to quickly charge many smartphones, tablets and some thin and light laptops that support USB Power Delivery.

For example, users can use the battery with a MacBook Air M1 or devices with equivalent capacity needs. For smartphones, 45W is enough to meet most iPhones and many Android phones, although the actual capacity depends on the charging protocol that each device supports. This also means that the number 45W is the maximum capacity of the battery, not the level that MagAir31 always maintains. When charging iPhone or devices with lower power receiving limits, actual power will be adjusted according to the device, battery capacity, and temperature. Similarly, with wireless charging, the maximum power level of 25W can only be achieved when the phone supports the corresponding standard and power level. With the iPhone 15 Plus in my test, the actual capacity is lower due to the device's wireless charging limitation.

Summary

Mazer MagAir31 has a reference price of about 1.69 million VND. This is a backup battery aimed at people who need 10,000 mAh capacity but still want a relatively thin design, with both wireless charging and high-power USB-C. Besides performance, what I appreciate about MagAir31 is how Mazer combines 10,000 mAh capacity, a body about 17 mm thick, maximum 25W wireless charging and 45W USB-C in a device of just over 200 grams.

In return, the product does not have an integrated stand and when attached to the phone still creates a significant amount of weight if held for a long time. But if you prioritize a compact, large-capacity backup battery that can be charged wirelessly when you need convenience and switch to 45W USB-C when you need speed, MagAir31 is a fairly balanced choice. Those interested in the product can see more here. Thank you TLC for accompanying me on this article.