> first distinguish: * * normal fluctuation vs fault instability * *. When the portable power supply is charged to the later stage, it will change from constant current to constant voltage, and the current will slowly drop and jump slightly, which is normal; The fault is that the current jumps back and forth, it is intermittent, and the charger starts and stops burping repeatedly.
# # 1. Give priority to simple screening (don't disassemble, try in sequence)
1. ** Confirm that the charger specifications match * *
Try to use the original adapter; The voltage, power and fast charging protocol should match the portable power supply. The adapter power is too small, the protocol handshake fails, the power will be negotiated repeatedly, and the current will continue to beat.
2. ** Replace wires, plugs and sockets * *
The most common reasons are thin core diameter, internal disconnection and loose plug oxidation. Change a * * high-power E‑Marker fast charging line * *, change a wall independent socket, and don't share the power strip with the induction cooker and air conditioner (grid voltage fluctuation).
3. ** Improve heat dissipation * *
Chargers and portable power supplies should not be stacked, covered with cloth and placed in a ventilated place. Overheating will trigger temperature control to reduce power, and it will recover when it is cooler, which is characterized by periodic current jump and intermittent current drop.
4. ** Clean the interface * *
Clean the dust wool with a dry brush at the power input port and the charger output port, and the oxidation contact will be cut off intermittently.
5. ** Distinguish whether the charger is broken or the portable power supply itself is broken * *
Use this charger to charge other equipment of the same specification; Charge this portable power supply with a known-good adapter.
-Just change the charger: * * The mains charger itself is faulty * *
-Changing the charger is still unstable: * * Problems with the charging board, battery core and protection board inside the portable power supply * *
# # Second, the charger itself is faulty (it can only be disassembled if it has an electronic foundation, and the * * high-voltage side has 220V V. Non-professionals are not recommended to disassemble it for maintenance, and direct replacement is preferred * *).
The most common damaged components:
1. ** Bulging and capacitance loss of input/output electrolytic capacitors (maximum output) * *: Filtering is invalid, ripple is large, and current jumps, so it is only necessary to replace the capacitors with the same specifications.
2. ** Virtual welding * *: Heavy fall and vibration lead to pin desoldering of transformer, optocoupler and voltage stabilizing element, and tapping the shell will change the current accordingly, so repair welding will solve the problem.
3. ** The optocoupler and TL431 voltage stabilizing loop are abnormal * *: the voltage stabilizing feedback is out of control and the output jumps back and forth.
4. ** The power management chip and switch tube are aging, and the load capacity becomes worse. Burp protection when loaded * *
# # Third, the portable power supply side causes the input current to be unstable (the charger looks unstable and the root cause is the power supply).
1. The battery cell is aging, the single series voltage difference is large, the internal resistance is soaring, and the voltage is constantly changing during charging, which pulls the charging current.
2. The built-in charging management board of the power supply fails, the protocol chip is abnormal, and the input MOS tube is unstable.
3. The battery protection board frequently triggers overvoltage/overcurrent protection and starts and stops repeatedly.
# # IV. Quick judgment and treatment scheme summary
-Wire/socket/heat dissipation is not up to standard: directly replace wire, socket and ventilation.
-Protocol and power mismatch: replace the original/regular adapter that meets the nameplate parameters.
-The internal capacitor, virtual welding and voltage stabilizing circuit of the charger are damaged: * * Ordinary users suggest replacing the adapter directly * *; Know the circuit and have a multimeter to replace the capacitor and repair the welding.
-damage to battery/charging board of portable power supply: battery maintenance is risky, so generally, the whole machine is directly repaired or replaced.
# # Safety reminder
There is a high-voltage energy storage capacitor inside the switching power supply, which will still store power after power failure. * * Do not disassemble the adapter shell without maintenance experience, which may cause electric shock.
