On March 15 this year, Love to play computer games Introduced the tricks in the mobile power industry, and How to select mobile power Put forward their own views. Many readers also hope that we can do a mobile power brand shopping guide recommendation, so it is easy to choose a mobile power. From today on, Iooki will also launch a series of mobile power evaluation, scoring the performance and price of mobile power as the basis for everyone to choose mobile power.

First of all, it brings you a cheap mobile power supply. On Taobao, we often see 28 yuan, 35 yuan and so on portable source Is this mobile power worth buying?

The following figure shows the "samples" we bought from manufacturers on Alibaba. The sample price is 30 yuan:

The design is very simple, with only input and output ports and an indicator light:

A number of similar products can also be seen on Taobao. From the shape of the mobile power supply, it can be seen that the power supply is built with a 18650 cell, with a nominal capacity of 2600mAh, and the price ranges from ￥ 16.83 (Nani?) to ￥ 45:

In order to measure the performance of this mobile power supply, we used the constant current test method to test the discharge current of 1A and 500mA respectively:

The above figure shows the constant current discharge curve of 1A. It can be seen that under the condition of constant current discharge of 1A, the initial output voltage is 4.8V. Almost an hour later, the discharge voltage drops to 4.05V, and the discharge is terminated.

Amplified discharge curve:

The mobile power supply has a nominal capacity of 2600mAh, but only 958mAh is output under the 1mA constant current discharge test environment. Its usable capacity ratio is:

958mAh/2600mAh=36.8%

If the conversion rate of the mobile power supply is calculated based on the output energy, the output energy of the battery is 4305mWh. If the output voltage of the ordinary lithium battery is 3.7V, the effective conversion rate is:

4305mWh/（2600mAh*3.7V）=44.8%

Before《 Neglected conversion rate 》We mentioned in the article that the cell capacity of the mobile power supply cannot be 100% converted to the digital device, but from the above data, the efficiency of this battery seems to be lower.

From the discharge curve, it can also be seen that the discharge of this mobile power supply is not stable. There is reason to suspect that the internal voltage stabilizing circuit of this power supply is not qualified, or even there may be no voltage stabilizing design. In order to further verify our judgment, we carried out a violent disassembly of this mobile power supply:

The disassembly results also verified our guess. As can be seen from the above figure, the mobile power supply is very simple in structure, with only one 18650 cell and a small circuit board.

Enlarged circuit board

The battery cell should be a new battery cell (the trace on the contact part between the metal sheet and the battery is glue), and it has also done a good insulation. The manufacturer is still quite honest, but it is hard to say about mobile power supplies with retail prices of only ten yuan.

Summary

Manufacturer/model: OEM/model unknown

Power capacity: 2600mAh

Reference price: 30 yuan (sample price)

Price score: ★★☆

Performance score: ★

Recommended index: ★ ☆ (not recommended)

In general, this product has good portability, but its practicality is biased, and it can only be used for temporary travel for a short time. In terms of price, as a 30 yuan product, this power supply is reasonable in price, but the lack of voltage stabilization and safety protection, unstable output voltage are the hard injuries of this product, and the input and conversion efficiency are also low, so it is not recommended.

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