Exploding Phones: Why It Happens, How to Prevent It
We often see news about the explosion of the
mobile phone wall charger, so many people will worry about whether the charger they use will explode inadvertently when using the charger, but in fact, as long as the charger is used correctly, it will not explode.
So what is the cause of the charger explosion?
First, the short circuit: the short-circuit caused by the explosion of the charger is less likely, because there is a protection circuit (in addition to the protection circuit can also be connected in series with PTC-like protection components), and the current flows through the PCB trace when short-circuited, it will burn PCB trace;
Second, the battery: due to internal defects of the battery, the battery itself explodes without charging or discharging. In this case, what we can do is to choose a better battery, such as a polymer;
Third, overload charging: The first situation is that the charging voltage is indeed too high, the voltage is greater than 4.3V when charging; the second case is that the two batteries themselves allow the maximum voltage is less than 4.2V, it is estimated that the former is highly likely. The countermeasures include protecting the IC overcharge and drawing 4.30V. Although the maximum allowable voltage of the battery is 4.35V, we should consider the discreteness, which includes the discreteness of the cell and the discreteness of the protection IC overvoltage value, and stay There is a margin. The Seiko protection IC was chosen because of its high overvoltage protection value and wide range of options (4.2-4.4). At the same time, the charging circuit should be strictly corrected to ensure that the maximum value does not exceed 4.25V.
The above three situations are some of the reasons for the explosion of the mobile phone
wall charger. Of course, the reason why the charger will explode is definitely more than these. We must use the charger correctly. Do not plug the charger into the plug. Do not pull it out, when the plug is always working, the continuous flow of current will cause the heat of the components, it is easy to cause an explosion, we must develop a good charging habit.