Issue: NB10000G3 makes Hissing/Buzzing/Sizzling noises when charging another electronic device.
Explanation : Internal
After consulting with the factory R&D, we have learned that the hissing/buzzing/sizzling sound is caused by insufficient suppression of high-frequency ripple. When the load-side circuitry (e.g. a phone) generates a larger ripple during operation, it can result in this kind of noise.
However, there’s no need for concern. This sound is caused by the piezoelectric effect of ceramic capacitors reacting to the ripple from the load side, which produces high-frequency noise. It does not pose any safety risks.
Also, this sound may not indicate an issue with our power bank. It could be related to the quality of the connected device. If the device has poor ripple control, it can be difficult for the NB10000 GEN3 to suppress the resulting noise fully.
How do we explain it to the buyer?
We spoke with the factory. The noise you noticed came from the piezoelectric effect of ceramic capacitors reacting to the ripple from the load side, resulting in high-frequency noise. This does not pose any safety risks. Some people are sensitive to this noise, while others cannot hear it. Could you test the power bank on another phone or device? The noise also depends on which device the power bank is charging.
We can certainly replace the unit if the noise is persistent.