Hello!
I would like to start today's material with a paraphrased advertising slogan: “Not all chargers are created equal.”
As you understand, today I would like to talk with you about chargers and their use to charge digital technology.
Considering the peculiarities of my hobby (phone repair), I often have to change the batteries in the phones and tablets of my friends and acquaintances. The main complaint is that it suddenly stopped holding a charge, or stopped charging over time. There are even worse cases, like in a recent patient of mine, to whom a swollen battery squeezed out a display module, breaking it.
What do batteries die from?
There are three main reasons.
- Violation of operating rules, such as operation in conditions of extreme temperatures, humidity, vibration, pressure.
- Defect in the manufacture of the battery (this can also include the use of non-original batteries of questionable quality).
- Using a charger of poor quality or incorrect parameters.
Remember these chargers with a red or white LED on top? They have destroyed hundreds of batteries.
Let's take a closer look at the third point. But, before discussing this topic, you need to remember what chargers are, and what parameters they have.
There is a huge variety of equipment that needs chargers. Today I would like to focus on chargers for smartphones and tablets.
Modern chargers have two main parameters to be guided by. This is the voltage, which for most chargers is approximately 5.3V (volts), and the amperage, which can vary significantly, ranging from 0.1A to 3A (amperes).
Among the most common values, several can be distinguished – 0.5A, 0.85A, 1A, 1.5A, 2A.
USB 2.0 in a computer is capable of delivering a current of no more than 0.5 amperes, or no more than 0.9 amperes (USB 3.0).
The higher the second value, which is commonly referred to as 'amperage' for simplicity, the faster your device's battery will charge.
Typically, the larger the battery capacity, the more amperes it takes to charge it. Some high capacity batteries are configured so that they will not charge from a low capacity charger. Therefore, do not charge a tablet with a large battery from a USB 2.0 port. The device will either take a very, very long time to charge, or it will refuse to charge at all.
In addition, chargers differ, according to the principle of operation – pulse and transformer.
To simplify greatly, then transformer chargers are heavy and rather large chargers (due to the massive transformer) that lower the voltage and rectify the current, making it constant.
Pulse chargers are lighter and smaller than transformer ones. Impulse chargers are the most common at the moment. This is not least due to their weight and size characteristics. Unlike transformer, pulse chargers work due to a high-frequency voltage converter (inverter), and charge the battery with a series of high-frequency pulses of electric current.
Both have pros and cons.
Transformer chargers charge the battery more slowly, but with better quality. Pulse is faster and not as good. Electrical engineers will swear at me, but I will say that in the case of transformer chargers, the charge is denser, and the battery lasts longer (tested on most of my phones).
It is believed that charging with ultra-low currents with transformer chargers harms lithium. However, this claim has been disproved by studies suggesting that the damage the charger does to lithium is so minor that it can be neglected.
At the same time, transformer storage devices are more demanding on the quality of power grids and voltage stability in the network. Pulse ones are less demanding on the quality of these same networks and have better protection against voltage surges.
And once again we repeat that pulse chargers are much lighter and more compact than transformer ones, which most likely predetermined their dominance.
How does this all affect your phone?
Both transformer and pulse chargers charge the battery of your device in about the same way and, in the case of high-quality performance, should not damage the battery of the device.
In addition, inside the battery of modern devices, there is additional protection in the form of a controller, which does not allow the battery to receive more charge than it should.
However, if the matter were only in the values of these two parameters, then there would be no problems.
Much more dangerous is the fact that unknown Chinese factories that assemble chargers 'on the knee' often use cheap components of extremely low quality, which leads not only to a violation of the output nominal values, but also to their floating values, when voltage and current change abruptly during charging. within unpredictable limits.
And if it is more difficult to screw up in the production of transformer chargers, then in impulse chargers, there is plenty of room for the evil Chinese genius to roam around.
Most of the time, the controller in the phone or tablet battery handles this kind of violence, and we don't notice it. However, this is not always the case.
Working in extreme modes is not beneficial to any device. The resource of microcircuits develops faster, and sooner or later the principle “where it is thin, there it breaks” will work. It was then that we were surprised to find that the battery began to hold very poorly. And sometimes we see a visual embodiment of the problem – our device is swollen and no longer wants to work as before.
There are other reasons for the death of a battery, one of which is the use of a cable of questionable quality.
Yes, the cable, the one that goes from the charger to the phone, is also very important. Poor soldering of contacts. Non-compliance with the connection diagram of the contacts. Reverse polarity. Poor connector. All these troubles can await your phone when using a low-quality cable.
How to avoid this?
The answer is outrageously simple – avoid buying chargers of dubious quality in unverified places. A charger for 50 rubles cannot work in the same way as a charger for 350-500 rubles.
Among the people who brought me electronics for repairs with a problem – the battery does not work, most used cheap noname-chargers, bought on the 'just to be cheaper' principle. It is often necessary to explain to a person that using such chargers is not only harmful, but also dangerous. Some believe and draw conclusions, while others are skeptical about this information and continue to take risks.
But, in addition to low quality chargers, the batteries of modern gadgets have two more enemies – “constantly on charge” and “completely discharged”.
The leader in the first case is the car charger. More often than not, a phone or tablet in a car is 'on charge' 100% of the time. The rechargeable battery has such a parameter as the number of cycles during which the battery will remain functional. Constantly connected to a charger, it is in extreme mode.
Image via technodenny.com
Most chargers, when the battery reaches 100% charge, turn off the power supply to the battery, continuing to measure the voltage on the battery. As soon as the voltage drops below the values typical for one hundred percent charge, the charger starts charging the battery again to one hundred percent. And this happens in most cases. Add to this a Chinese charger for 50 rubles, and it becomes clear in what extreme conditions such a battery has to exist.
In the second case, the device is used on the 'until it turns off' principle. This is partly due to previous experience with nickel-metal hydride batteries, which had a memory effect, and which were recommended to be discharged to zero before the next charge. Lithium does not like deep discharge. Deep discharge of a lithium battery leads to its degradation.
Therefore, to the recommendations to use high-quality chargers and cables, you can safely add the recommendation not to leave your phone or tablet on charge for too long and not allow a full discharge.
conclusions
From the main recommendations that can be derived from all of the above, several key ones can be distinguished.
- Use chargers and cables from manufacturers that have proven themselves in the market on the positive side, and ideally, only the original charger.
- Do not keep the device 'on the wire'. Charge until fully charged and then disconnect from the charger.
- Do not let the battery discharge to zero, since lithium does not like deep discharge.
- If most of the time you charge the device by leaving it on the wire all night, it makes sense to use a charger with a small current value (0.5A – 0.3A) for this purpose.
- If possible, use a transformer charger.
Yes, the last point is not unambiguous, and may cause controversy, but as a defense of this point of view, I can say that for the entire time of using all my phones, of which there were more than fifty. None of them had a swollen battery, although almost all of them were often charged with a low power transformer charger.
And instead of an afterword, I want to ask you, dear readers, how important is this parameter for you? How carefully did you choose the charger for your device, if the need arose?