There is a DC-DC conversion circuit inside the charging treasure, which is working in the oscillation state, if the inductor's magnetic core is loose, it may be able to hear a weak sizzling sound in a very quiet environment, just like the electric mosquito clap can also be heard, this is not a fault, you can rest assured to use.
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1, the lithium battery of the charging treasure is the same as the mobile phone, most of them are 3.7V, such a voltage is unable to charge the mobile phone, so the charging treasure will increase the voltage to about 5V, this process needs to boost the voltage coil, you hear the sizzling sound is issued by it, the better charging treasure may sound relatively small.
2, the inductance on the mainboard of the charging treasure occurs in the high-frequency electromagnetic resonance, which has nothing to do with it. General electric magnetic resonance components include transformers, inductors, chokes, and so on. High-grade components will use epoxy resin to fill these components, resist resonance, enhance thermal conductivity, enhance sealing, isolate moisture and so on.
3, charging treasure is generally polymer battery: according to the different electrolyte materials used in lithium ion batteries, lithium ion batteries can be divided into liquid lithium ion batteries, referred to as LIB, and polymer lithium ion batteries (referred to as LIP) two categories.
The positive and negative electrode materials used in polymer lithium-ion batteries are the same as liquid lithium ions, and the positive electrode materials can be divided into lithium cobaltate, lithium manganate, ternary materials and lithium iron phosphate materials, and the negative is extremely graphite, and the working principle of the battery is basically the same. The main difference between them is the difference in electrolyte, liquid lithium ion batteries use liquid electrolyte, and polymer lithium ion batteries are replaced by solid polymer electrolyte, this polymer can be \"dry\
Should be current sound, can consider replacing after sale
Xiaomi mobile power uses LG\/ Samsung's top lithium-ion battery, the latest USB intelligent control chip and charge and discharge chip from Texas Instruments. Due to the use of the latest USB intelligent control chip and charge and discharge chip of Texas Instruments, this mobile power supply has multiple protection functions, such as temperature protection, short circuit protection, input overvoltage protection, input anti-reverse protection and so on.