Will shared power banks be the next mobile bombs?

Recently, the safety issues of various power banks have been making a big stir. There have been cases of swelling, fires, and even large - scale recalls. As a result, passengers now have to go through a special security check for power banks when taking airplanes or high - speed trains.

However, these safety hazards are not exclusive to personal power banks. Shared power banks are also deeply involved. Simply enter "shared power bank catches fire" on various platforms, and you can retrieve a large number of news reports.

It seems that this thing is not very reliable.

In order to figure out the materials and safety of shared power banks, we specially bought out the shared power banks of four of the most common brands on the market, namely Meituan, Monster, Xiaodian, and Jiedian, and disassembled them to show you their workmanship and materials.

In fact, as soon as these shared power banks arrived, Tony noticed some problems.

For example, the 3C certification that everyone is most concerned about. Although each brand has marked various safety certification signs on the shell, only two of them have the 3C logo printed on them.

As for the other two, it's unclear whether they were produced earlier and missed the mandatory 3C certification, or the manufacturers just wanted to take the easy way out and didn't plan to get it.

Regarding the two power banks with 3C certification, Tony also conducted a query. After checking with the data of the Quality Certification Center, no cases of false 3C marking were found for now. It seems that they are still somewhat reliable.

However, it should be noted that when renting a power bank, it's still impossible to know in advance whether the borrowed one has 3C certification. Currently, neither the rental machines nor the mini - programs provide relevant information. So, whether you can rent a power bank with 3C certification is a matter of luck.

For example, during our test this time, there was an extreme counter - example. By luck, Tony rented an ancient power bank dated back to 2018 on the first try.

Considering the consistency of the test, Tony later had to spend 99 yuan to randomly rent another shared power bank of the same brand in the mall to get one with a relatively recent production date.

But you won't know this information without disassembling the power bank. Some shared power banks that seem to be in good condition may actually be several years old.

However, although the appearance of the 3C logo on shared power banks is rather random, through disassembly, Tony found that generally, the workmanship of the shells of each brand is quite solid.

For example, in terms of the safety protection of the battery cells, each brand uses plastic support plates or buffer foam for protection.

Some brands' shells are so sturdy that Tony spent more than half an hour trying to open the protective shell.

Therefore, you can rest assured on this point. Even if there are minor bumps during use, there's no need to worry too much about a fire.

When it comes to the battery cells, each brand is different. In terms of the form of the battery cells, except for the old - model power bank of one brand that uses 18650 cylindrical battery cells, the rest use soft - pack battery cells.

Only two brands have the 3C logo printed on their battery cells, and the suppliers of both are Amprius, which is the brand of battery cells that was accused of cutting corners in the recent power bank explosion incident.

Although this brand has a bad reputation in this round of power bank incidents, Tony still wants to mention that not all Amprius battery cells will have short - circuit problems.

If you're not very confident, it's recommended to check on the official website of the Quality Center to see if the model on the power bank shell is on the list of revoked 3C certifications.

Here are the specific market launch time and the source manufacturers of the battery cells for your reference:

These are only the data of the power banks disassembled this time and do not represent the overall products of the brands.

In addition to the battery cells, problems with the hardware circuit can also easily lead to safety issues with power banks.

Fortunately, these power banks don't have obvious defects in the circuit. Especially in terms of safety protection design, they are all quite well - done.

For example, each brand has added a power protection IC to the circuit, which is paired with a MOS tube to protect the battery from over - charging, over - discharging, and over - current.

In terms of temperature control, these brands have also carried out relevant monitoring and protection. Unexpectedly, the temperature control protection that Romoss has been cutting corners on and not fully implemented is a standard feature for these shared power banks. Isn't it a bit ironic...

However, after a careful inspection, Tony found that the installation methods of the NTC (thermistor) for several shared power banks are slightly different.

For example, some brands integrate the NTC on the PCB and connect the battery cell to the NTC on the PCB through thermal conductive silicone to achieve temperature detection.

Other brands stick the NTC on the battery cell for detection and connect it to the PCB through flying wires.

The functions achieved are quite similar. If we have to make a comparison, Tony thinks that the stability of the second solution is slightly better.

After all, no matter how good the thermal conductivity of silicone is, it's not as accurate as having the sensor directly measure the battery itself.

Moreover, Tony also noticed some small details of the manufacturers on the PCB.

For example, some manufacturers specifically apply three - proof glue on the PCB to improve the reliability of the circuit. In terms of welding, some manufacturers also have higher requirements for the process.

So, in terms of safety, shared power banks still have a certain degree of guarantee. If there are problems, it's more likely to be with the battery cells.

By now, you must have noticed that shared power banks are indeed well - designed.

Maybe the manufacturers have thought it through. Instead of having the news of their power bank racks with glowing logos catching fire go viral on the Internet, it's better to invest more in materials to prevent problems before they occur.

However, this doesn't mean that we'll recommend shared power banks to you in this article. Compared with their efforts in safety, the actual charging experience of shared power banks can be described as "a competition in badness".

First of all, the nominal power of the shared power banks disassembled by Tony is around 10 - 15W. Compared with the "hundred - watt fast charging" of current manufacturers, it can be said to be far behind and unprogressive.

This is actually the old trick of shared power banks that we've been talking about. If they charge fast, how can the stores charge hourly rentals? So, the slower the charging power of shared power banks, the more profitable it is...

Moreover, in our actual test, there was a strange phenomenon where an old - version Jiedian power bank from 2018 could only charge an iPhone at a power of 2.6W...

Let me explain it to you like this. This charging power may even be slower than charging your phone by plugging it into the USB port of a computer...

Except for this special case, the measured power data of the other four power banks (including the new - version Jiedian power bank) are not very different from the nominal values.

Here are the specific power test data for your reference:

These are only the data of the power banks disassembled this time and do not represent the overall products of the brands.

In addition, Tony also encountered some situations that affected the experience when renting power banks this time.

As Tony mentioned before, although the power banks for this test were randomly bought out, he still got such an old - fashioned one.

During the rental process, Tony found that it's quite common to have a mixture of new and old power banks for rent in the market