In less than 20 minutes to 100 percent – when the smartphone battery is empty, recharging can not go fast enough.
Some manufacturers are now offering mobile phones with quick-charging technology, which recharges the battery with electricity in a very short time. Many models such as Apple’s iPhone or older Samsung Galaxy S devices can at least be charged more quickly if you use a more powerful charger than the standard plug.
Can every mobile phone be charged faster with this trick?
“Not every cell phone charges faster when I connect it to a powerful charger,” says Prof. Maximilian Fichtner (61) from the Karlsruhe Institute of Technology (KIT). The maximum speed when loading will be from Smartphone itself is limited, according to the expert.
“There is a kind of valve, the so-called Battery Management System, or BMS for short, that monitors and regulates the charge level of the battery. So there is no longer a risk that the battery will be damaged immediately if you connect the wrong charger,” says Fichtner in an interview with BILD. “Whether a mobile phone can be charged quickly depends on the type of battery that is installed.”
Prof. Maximilian Fichtner from the Karlsruhe Institute of Technology
Which model charges fast?
Whether a mobile phone can be charged quickly can be found in the manufacturer’s technical information. “Otherwise you can tell from the charger that comes with the cell phone,” explains Prof. Fichtner.
The charger is printed with how many amps of charging current it delivers. “The standard is 2.5 to 3 amps or 2500 to 3000 milliamps. Higher values mean faster loading.”
Not so clever – when charging you should avoid heat build-up on the back
Better load on your back
The life of the battery usually does not suffer from fast charging. “There is only a risk to the service life if the battery heats up too much during charging,” says Prof. Fichtner.
“If a mobile phone is often left in the sun while charging, the high temperature can cause aging processes in the battery, which ultimately lead to the storage capacity of the battery decreasing. That’s why you shouldn’t charge your cell phone under your pillow or blanket, because it can get hot,” says the expert.
“And another simple trick to let heat escape while charging: the cell phone or that Simply turn the notebook on its back.”
In modern smartphones, the BMS also controls the temperature of the battery and prevents charging above a certain level if the recommended battery temperature is exceeded.
Loaded fast = empty faster
If you charge your cell phone quickly, you may experience a surprising phenomenon: the battery is also empty more quickly! Because it stored less electricity than would actually be possible.
Prof. Fichtner: “It is actually possible that the capacity of a very quickly charged battery is lower, for example only 90 percent instead of 100 percent. This is due to the chemical process that takes place inside the battery during charging. Lithium ions move into a graphite structure at the negative pole, as if you put a lot of balls on a shelf. If this happens at very high speed, the balls are no longer optimally packed on the shelf. If the battery then gives off electricity, fewer balls come out of the shelf.”
The good news: “This loss of capacity develops back with every normal fast charging process,” says Fichtner.
The ideal charge level
For many years it has been recommended that the battery charge level should ideally be between 30 and 80 percent. Otherwise there is a risk of losing battery capacity. “In principle, that’s true, but you don’t have to follow it strictly because cell phones are now smarter and use tricks,” says Prof. Fichtner.
“If the screen shows 100 percent battery level, for example, it’s only 90 percent in real terms, and there’s also a buffer of ten percent downwards when discharging. This prevents the battery from being fully charged or discharged,” says the expert.
The background to the 30 to 80 percent rule is the chemical process that takes place in the battery during charging and discharging. “Lithium ions migrate back and forth between two storage structures on the plus and minus poles like balls being moved from one shelf to the other,” explains Fichtner. “The balls act like pillars on the shelves at the same time. Therefore, it should be avoided that one of the shelves is completely emptied. Otherwise it would become somewhat unstable mechanically, and the battery could lose capacity.”
Occasionally fully discharged
Prof. Fichtner knows that occasionally draining the battery down to zero percent has a positive effect. However, this has nothing to do with the chemical processes in the battery, but with the level indicator: the charging software of the mobile phone is recalibrated when the battery is discharged.
“The mobile phone reads the voltage of the battery, which drops when discharging, and assigns it to a specific charge level,” explains Prof. Fichtner. “The fully discharged state is then set as zero percent, and then when I have fully charged again without interruption, it is 100 percent. This results in a discharge curve that indicates the battery level as a percentage.”
Because the battery changes over time, it’s a good idea to completely drain and calibrate it occasionally to get a more accurate percentage, advises the battery expert.
It is better not to charge old mobile phones and then put them in the closet
Fire hazard from old cell phones?
If you store an old smartphone at home, you risk a lot To report in the worst case that the device catches fire on the Internet. Is that actually possible?
Prof. Fichtner: “If the battery is discharged, you can actually rule out this danger. Then all components are in a harmless form. But if the battery were still charged, a short circuit could cause a reaction that would heat up the battery, causing it to burst open and catch fire.”
That’s why it’s better not to charge an old cell phone – and rather to Recycling than leaving it in a drawer at home.