Why Xiaomi is charging for a long time: technical reasons and ways to accelerate

Xiaomi smartphone owners often face the problem of slow charging — the device is connected to the network for two hours, and the percentage of the battery barely moved. Especially annoying when everything used to work quickly, and now even night charging does not save from discharge to lunch. What is the reason for this behavior? The culprits can be both hardware malfunctions (cable, power supply, battery) and software failures (background processes, optimization of MIUI). In this article, we will analyze all possible scenarios, from banal wear of the cable to hidden energy saving settings that inhibit charging.

It’s important to understand that Xiaomi’s fast-charging models (like the Redmi Note 12 Pro+ or Xiaomi 13T) can lose up to 40% of their charging speed due to an inappropriate power supply or smart charging mode. Budget devices like the POCO M5 or Redmi 10A aren’t designed to be lightning-fast-recovery – slow-charging can be a design feature.

Before you run to the service center, check the simple things: do you use a cheap cable from a set of headphones or a charger from another device? Even if they "seem to fit," the difference in current strength can be critical. Now let's get to the detailed reasons.

1. Problems with charger or cable

To start with the obvious, power supply and cable, which are statistically linked to 60 percent of the time, cheap Chinese charging (even if it's "original" with AliExpress) often doesn't give you the declared power, like a 33W unit can only really give you 10W, and your Xiaomi will charge like the old Nokia 3310.

How to check:

• 🔌 Connect another charger (preferably original from Xiaomi or certified Quick Charge) 3.0/4.0).
• 📱 Try charging another phone with the same cable - if it's charging slowly too, the cable is a problem.
• 🔍 Check the connector. USB-C on the phone: Pollution or deformation of contacts can interfere with normal charging.

Pay attention to the power supply:

⚠️ Note: Use a power supply with higher power than the phone supports (e.g. 120W for Redmi) 9A), It will not speed up charging, but it may damage the power controller.

Battery wear: when the battery is no longer the same

The lithium polymer batteries in Xiaomi smartphones are designed for 300-500 full charge cycles, and then their capacity starts to fall steadily and their charging speed decreases. If your phone is older than 2 years, there is a good chance that the battery is worn out, and you can check this through a hidden menu or an application like AccuBattery.

Signs of a worn-out battery:

• 🔋 Phone's running out of power. 3-4 hourly with moderate use.
• 🐢 Charging stops at 80-90% It does not go on (the protection against overheating is activated).
• 🌡️ The body is very hot even with normal charging.
• ⚡ Charging "jumps" (50 percent, then 30% in a few minutes).

To know the battery status:

1. Enter the dialer code ##4636##.
2. Go to the section "Battery Information".
3. Look at the level and health settings, and if health shows "bad" or below 70 percent, it's time to change the battery.

⚠️ Note: If the battery capacity has fallen below 60% of the nominal, some Xiaomi models (e.g. Mi 11 or Redmi) K40) Automatically limit charging current to 500 mA – this is fire protection.

3. Smart Charging or other energy-saving features are enabled

The MIUI has several hidden features that can artificially slow charging, most famously Smart Charging, which limits the charge to 80% to extend battery life, and is activated automatically after upgrades or when connected to charging for long periods (such as at night).

How to turn off "Smart Charging":

1. Go to Settings → Battery and Performance.
2. Select Battery Settings → Smart Charging.
3. Turn off the slider or set up a schedule (if necessary).

Other energy-saving modes that interfere with charging:

• 🔄 Balanced mode in battery settings – limits background processes, but sometimes charging current.
• ⚡ "Super Energy Saving – blocks fast charging until you turn off mode.
• 🌙 "Sleep mode" (in some firmware) - can turn off turbo charging at night.

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If after turning off the "Smart charging" speed is not restored, restart the phone - sometimes changes are applied only after the reboot.

4.Overheating phone: why Xiaomi "strangles" charging when heated

Xiaomi has multi-layered overheating protection for its smartphones, and if the temperature of the processor or battery is above 40-45°C, the power controller automatically reduces the charging current or even turns it off, which can occur even in normal use if:

• 🎮 You play heavy games (Genshin Impact, Call of Duty Mobile) while charging.
• ☀️ The phone lies under direct sunlight or in a stuffy room.
• 🔥 Charged in a case (especially silicone or thick armored).

How to check the temperature:

1. Install the AIDA64 or CPU Monitor app.
2. Look at the temperature of the battery and the processor.
3. If the values are above 40°C, let the phone cool for 10-15 minutes.

What to do if the phone overheats:

Remove the case | Charge in a ventilated location |Do not use your phone for games/video |Disable background apps |Use the original charger-->

⚠️ Warning: If the phone is heated to 50°C and above without load (just lying on the table), this is a sign of a malfunction of the battery or motherboard!

5. Software failures: viruses, background processes and “curved” firmware

Sometimes slow charging is not due to hardware, but to software conflicts, and here are the most common reasons:

• 🤖 Viruses or malware – some Trojans specifically load the processor to drain the battery faster.
• 📱 Informal firmware (e.g. custom firmware) MIUI Third-party developers may not control the power controller correctly.
• 🔄 Hanging background processes – for example, constant sync of Google Photos or Mi Cloud.
• 🔧 Failures after update MIUI — Especially relevant for betta versions.

How to diagnose the problem:

1. Check your phone for viruses with Malwarebytes or Dr.Web Light.
2. Go to Settings → Applications → Permissions → Autostart and disable autorun of unnecessary programs.
3. Check battery consumption in Settings → Battery → Battery Use. If an application consumes >10% in the background, remove or limit it.

If the failures started after the MIUI update, try:

Failure of the charging port or power controller

If all of the above methods fail, the problem may lie in a physical malfunction:

• 🔌 Oxidation or contamination of the connector USB-C — dust, moisture or corrosion disrupt contact.
• 🔧 Damage to the power controller (often after falls or moisture intrusion).
• 🔋 Battery bloating – can put pressure on the motherboard, causing failures.

Signs of hardware breakdown:

• 🔌 Charging is only in one position of the cable (you need to "twitch" the plug).
• ⚡ The phone is charged with “twisting” (it goes, it stops).
• 💥 The screen displays a warning that says, "Charging is suspended. Check the cable" even with the original cable.

What you can do on your own:

1. Clean the charging port with a toothpick (carefully, without scratching the contacts) or compressed air.
2. Check if the battery is swelling, put the phone on a flat surface and spin it around, and if the case is playing or there are gaps, the battery needs to be replaced.

⚠️ Warning: If the charging port is damaged (e.g. bent contacts), do not try to repair it yourself! This can lead to a short circuit.

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If the phone stopped charging at all or shows “No Charging Supported,” there is a 90% chance that the USB-C port or power controller is to blame.

7. Features of models: why some Xiaomi charges slower than others

Not all Xiaomi smartphones are equally fast in terms of charging, and even within the same lineup, there are differences:

• 📱 Budget models (Redmi) 10A, POCO M4) — often limited to the charging of 10-18 Here, slow charging is the norm, not a breakdown.
• ⚡ Flagships (Xiaomi) 13 Ultra, Mix Fold 3) — support 67-120 W, but can brake due to overheating or power-saving modes turned on.
• 🔋 Large battery models (Redmi Note 12 Pro)+ 5000 mAh battery – even at 120 W full charge takes ~30 minutes, but the last 20% may go slower (battery protection).

Example: POCO F5 with support for 30 W will charge 2 times slower if you use a power supply of 10 W. And Xiaomi 12S Ultra can “brake” charging up to 50% of the speed, if you simultaneously turn on wireless charging and reverse charging (for example, for headphones).

Comparison of charging speed of popular models:

FAQ: Frequent questions about Xiaomi's slow charging