There is a DC-DC conversion circuit, which is working in the oscillation state, if the inductor core is loose, it may be able to hear a weak sizzling sound in a very quiet environment, just like an electric mosquito clap can also be heard, this is not a fault, you can rest assured to use. Note: Do not adjust the output voltage to higher than the equipment voltage, otherwise it may cause equipment damage, please be sure to acknowledge before use. Please use the specified charger. Stop short-circuiting, differentiation and throwing into the fire.
Do not disassemble chargers and batteries to modify them. Pay attention to moisture and waterproof. Please put this product away when shelving, avoid playing as a child's toy.