Why Xiaomi phone discharges while charging: a full analysis of the problem

You've connected Xiaomi to a charger, but instead of the usual increase in battery percentage, you see the opposite picture: the charge indicator is creeping down, and the phone is discharged right before your eyes. The situation is not just annoying, it jeopardizes the device's performance. What is the reason for this behavior, and how to return the smartphone to normal charging mode?

The problem of not charging but draining when connected to the network can be related to hardware faults (damaged cable, connector, battery) and software failures (background processes, firmware errors). In this article, we will analyze all possible causes, offer diagnostic methods and give step-by-step instructions for Redmi, POCO and Mi models of different generations, paying special attention to hidden MIUI settings that can block charging, and common user errors when using fast chargers.

1. Checking the charger and cable: where to start the diagnosis

The first thing to rule out is a charging kit malfunction, and even Xiaomi's original accessories wear out over time, and cheap ones often don't match the claimed specs.

• 🔌 Connector. USB-C/Micro-USB: Check for contamination, oxidation, or mechanical damage, and often the contacts inside the connector are bent or covered by plaque, which impairs the current transmission.
• 📱 Cable: Bend it in different places — if you see fractures or bare wires, the cable must be replaced.
• ⚡ Power supply: try charging your phone from another adapter (preferably the original one). If the problem has gone away, your charger has failed.

To objectively check, use a multimeter or a special application like AccuBattery (available on Google Play), which will show the real current and voltage coming to the battery.

If the app shows values well below normal (for example, 0.3A instead of 1.5A), this confirms a problem with the cable or adapter.

⚠️ Warning: Never use chargers with power higher than your smartphone supports. e.g. Redmi Note 8 connection (max. 18W) adapter 120W It can cause the power controller to overheat and cause irreversible battery damage.

2. Diagnostics of the charging connector: when to blame USB-port

The charging connector is one of the most vulnerable places in a smartphone, and the dust, moisture, and frequent connections/disconnections of the cable cause wear and tear, and if the phone doesn't charge, it discharges when it's connected to the network, it can be:

• 🧹 Contact contamination: dust or debris builds up to prevent the plug from fitting tightly. Clean the connector with a wooden toothpick or compressed air.
• 💧 Oxidation: If the phone has come into contact with moisture, the contacts will produce a green coating. Remove it with alcohol and cotton swab.
• 🔧 Mechanical damage: bent or broken contacts require repair at a service center.

To check, connect your phone to your computer through the same cable, and if the device is not detected or the connection is interrupted, the problem is exactly the connector, and also try to push the cable slightly in different directions while charging, because if the percentage of the battery starts to rise, this confirms poor contact.

On some Xiaomi models (such as the Redmi Note 10 Pro or Mi 11), the USB-C connector has additional pins for fast charging, which damage causes the phone to recognize the connection but cannot get enough power, causing the battery to continue to drain despite the connection to the network.

3. Battery: wear, bloating and hidden defects

The average lifespan of lithium-ion batteries is 2-3 years (or 500-800 charge cycles), after which the capacity decreases and the internal resistance increases, which can lead to a paradoxical situation: the phone runs out when connected to charging, because there is not enough energy even to power the system.

Signs of a worn-out battery:

• 📉 Fast discharge (less than 4-5 hours with moderate use).
• 🔥 Overheating of the battery during charging or operation.
• 💨 Bloating of the body (especially noticeable if you put the phone on a flat surface - it will swing).
• ⚡ Sharp jumps in charge level (for example, from 50% to 1% in a few minutes).

Check the status of the battery through the engineering menu or applications like AIDA64 or CPU-Z. Pay attention to the parameters:

• Battery health: It should be “good.”
• Battery temperature: the norm is up to 40 ° C when charging.
• Battery capacity: If less than 80% of the factory battery, it is time to change the battery.

⚠️ Warning: If the battery is swelling, stop using the phone immediately. The risk of fire or explosion when further charging is extremely high.

On Xiaomi models with a non-removable battery (for example, Mi 9, Redmi K40), replacing the battery requires disassembling the device. Do not try to do this yourself without experience - you can damage the plumes or power controller. The cost of replacing in official Xiaomi services varies from 1,500 to 4000 rubles depending on the model.

4. Software failures: when firmware or applications are to blame

If the hardware is fine, but the phone still runs out when charging, the problem may be in the software.

• 🤖 Failures in MIUI: errors in energy-saving algorithms or power controllers, such as after upgrading to MIUI 14 Some Redmi Note 11 users complained about incorrect display of charge level.
• 📱 Background processes: applications that consume a lot of energy (for example, games, navigators or cryptocurrency miners).
• 🔄 Reboot cycles: If the phone is constantly rebooting while charging, it may be caused by corrupting system files.

For diagnosis:

1. Go to Settings → Battery → Battery Use and check which applications consume the most power.
2. Run your phone in safe mode (hold the power button → Safe Mode) If this mode is charging normally, it's third-party software that's to blame.
3. Reset the settings to factory (Settings → About the phone → Reset settings), pre-saving the data.

Some Xiaomi models (such as the POCO X3 or Mi 10T) have a hidden feature to turn off fast charging, which can work due to overheating.

1. Go to Settings → Battery → Battery settings.
2. Find the "Fast Charging" item and turn it on.
3. If you don’t have an option, try resetting your battery settings via the engineering menu (#4636###).

💡

If your phone only runs out when charging in certain applications (like games), try limiting their background activity. → Annexes → Application management → [play-off] → Battery → Limit background activity.

5. Power controller: latent malfunction

The power controller (PMIC) is a chip that distributes power between the components of a phone, and if it fails, the phone can behave in an unpredictable way.

• Show charging, but do not increase the percentage of the battery.
• Discharge even when connected to the network.
• Only switch on from a certain charger.

Causes of Controller Failure:

• ⚡ Voltage surges (for example, when using low-quality chargers).
• 💦 Moisture on the motherboard.
• 🔥 Overheating due to prolonged play or exercise.

Diagnosing a controller malfunction is difficult on your own, but there are indirect signs:

• The phone does not turn on without a charger connection, even if the battery is charged.
• Charging is only in the off state.
• The screen displays a warning that says, "Charge suspended. Temperature too high," even though the phone is cold.

Repairing the power controller requires professional equipment (sweeping station, microscope) and costs from 2,000 to 6,000 rubles. In most cases, it is cheaper to replace the motherboard entirely, especially on budget models like the Redmi 9A.

⚠️ Warning: If after a fall or impact, the phone stopped charging, do not connect it to charging until diagnosis! Damaged components of the board can cause a short circuit and permanently disable the device.

6.Fast charging: why it can hurt

Quick Charge, HyperCharge, Turbo Charge are convenient, but they have the opposite side. At high currents (from 3A), the load on:

• 🔋 Battery (accelerated wear and tear).
• 🔌 Charging connector (overheating contacts).
• 📱 Power controller (risk of failure).

On some Xiaomi models (such as the Mi 11 Ultra or Black Shark 4), users experience the phone discharge instead of charging when charging fast.

• 🔥 Overheating: if the battery temperature exceeds 45°C, the controller automatically reduces current or turns off charging.
• ⚡ Adapter incompatibility: for example, using charging from POCO F3 (33W) For the Redmi Note 9 (18W) This can cause protocol conflict.
• 📉 Battery wear: Old batteries can’t cope with high currents and begin to degrade even faster.

Decisions:

1. Turn off fast charging in settings (Settings → Battery → Battery settings → Fast charging).
2. Use only original or certified chargers.
3. Charge your phone at 10-35°C (not in the sun or cold).

💡

If your phone supports fast charging but you don’t use it regularly, turn it off in the settings, which will extend battery life by 20 to 30 percent.

7.When to contact the service: signs of serious breakdowns

If all of these methods have failed and the phone still runs out of charge, the problem may be more serious than it seems.

• 🔥 The phone heats up even without a load (the risk of battery fire).
• 💥 There are sparks or smell of burning when connecting charging.
• 🔌 The charger staggers or falls out of the case.
• 📵 The phone does not turn on at all, even when connected to the network.
• 🔄 The percentage of battery charge "jumps" or is reset to 0% immediately after the charging is turned off.

In official services Xiaomi diagnostics takes 1-2 days and costs about 500-1000 rubles.

• Replacement of the charging connector: 1,200–2,500 ₽.
• Battery replacement: 1,500–4,000 ₽.
• Repair of the power controller: 2,000–6,000 ₽.
• Replacement of motherboard: 5,000–15,000 ₽ (model).

Before the service visit:

1. Make a backup copy of the data (if the phone is turned on).
2. Write down the IMEI (*#06#) to help avoid replacement parts.
3. Check if the service uses original parts (ask for certificates).

⚠️ Warning: If the phone is warranty, don't open it yourself! This will void warranty obligations. Contact the Xiaomi Authorized Service Center with a check and warranty card.

FAQ: Frequent questions about Xiaomi's charging discharge