Xiaomi is the most popular domestic mobile phone in 2012. Every open order is sold out in a short time. With a huge user base, Xiaomi has also launched a series of accessories on its official website. What we want to test today is a mobile power supply sold by Xiaomi Mall at a price of 229 yuan (159 yuan during the Rice Noodle Festival). The model is MDY-04-AA.
The appearance and shell technology of the Xiaomi Mobile Power Supply are similar to that of Xiaomi 2. The width of the Xiaomi Mobile Power Supply is similar to that of Xiaomi 2, but it is slightly longer and thicker. Sometimes we use the mobile power supply to charge the mobile phone at the same time. It is convenient to hold the Xiaomi Power Supply and Xiaomi 2 together.
Xiaomi Mobile Power It adopts a simple design. The top is a standard USB output port. The power switch is on the right. After pressing it, there will be four small blue LED lights in the front center to display the power (each LED light represents 25% of the power). The left side is the MicroUSB charging input port.
Family portraits:
The content of the instruction manual is quite detailed. From the instruction manual, we can see that "up to 98% of the filling rate, 93% of the conversion rate, 91% of the space utilization rate" and other detailed instructions, which are rarely seen in other mobile power instructions. So is this mobile power supply as efficient as the manual says? Let's measure it.
The constant current test generator is still used, and the discharge current with standard output current of 1A and 500mA is tested.
The discharge current of 1A was very stable before 2 hours and 55 minutes, and the voltage began to decline gradually in the last 10 minutes or so. The discharge time was about 3 hours and 5 minutes, the discharge capacity was 3118 mAh, and the output energy was 14.42 Wh;
The above figure is a magnified view of the section with relatively large voltage fluctuation. It can be seen that the voltage fluctuation value is within 0.01V, and the stability is quite good.
The above figure shows the 500mA discharge curve, which lasts for about 6 and a half hours. The discharge capacity is 3437mAh, the discharge energy is 16.42Wh, the average voltage is 4.91V, and the discharge voltage is stable.
The overall fluctuation of the amplified discharge curve is still controlled within 0.01V.
Can the conversion rate of this mobile power supply reach 90% or more as stated in the manual? Let's calculate:
1A load, conversion rate=14.42Wh/(3.7V * 5055mA)=77.1%
500 mA load, conversion rate=16.42 Wh/(3.7 V * 5055 mA)=87.8%
We know that the conversion rate of mobile power under low current load is higher than that under high current load. Although the conversion rate of Xiaomi mobile power under 500 mA load does not reach the level of 93% in the manual, it is also very close. It is among the best mobile power supplies we have tested. What about its internal structure? Recently, the mobile power supply was disassembled by preview. Let's take a look (the following pictures are from ）：
The overall workmanship of the PCB is good. We can see that channel Mos, charging IC, PWM controller, filter capacitor and other components are all available;
The cell is ATL with a capacity of 18.81Wh.
Summary
Manufacturer/model: Xiaomi/MDY-04-AA
Power capacity: 5055mAh
Reference price: 229 yuan (official website)
Price score: ★★★ (RMB 229)/★★☆ (RMB 169)
Performance score: ★★★☆
Recommended index: ★★★★ (worth recommending)
In general, this product has a simple and compact appearance. It is suitable for business people and heavy game enthusiasts who go out to work. Its output voltage stability and conversion rate are excellent. The capacity of 5055mAh is slightly higher at 229 yuan. However, the mobile power supply is not only a parameter of capacity. From the perspective of cost performance, it is worth the money. Especially during the Rice Noodles Festival (4.9-4.10), it only sells for 159 yuan, It is worth recommending.
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