Xiaomi and Redmi smartphone owners often face a situation where a device that used to “gain” energy in an hour now warms up at the socket for half a day, especially when it happens with the original adapter that came with the kit.
Slow charging isn't just an inconvenience, it's a signal that the power system has failed, it can be a software glitch, physical damage to the contacts, or even wear and tear on the battery itself, and in this article we'll go into detail about all the possible causes and ways to fix them.
Before you bring your gadget into service, you should rule out simple factors. Often the problem lies in the elementary contamination of the port or poor-quality cable, which you replaced with a "similar." Let's figure out why your Xiaomi Redmi Note stopped charging quickly.
Problems with the cable and power adapter
The first thing to check is the USB cable itself, and even if it looks whole, the veins that transmit high-power currents could break inside, and cheap cables often can't handle the load they're supposed to be carrying, and they can't run the Quick Charge or Power Delivery fast-charging protocol.
The second suspect is a power supply. If the adapter falls, overheats, or just fails because of a power surge, it can continue to supply current, but only at minimal speeds (usually 5 volts), a protective mode that prevents the unit from exploding, but charges the phone for hours.
⚠️ Attention: Use of unoriginal cheap power supplies with labeling «120W» or «67W» It can cause the power controller on your smartphone’s motherboard to fail.
Also worth paying attention to the length of the cable: too long wires (more than 1.5-2 meters) have more resistance, which leads to a drop in voltage. For fast charging, it is better to use short, high-quality cables with thick veins.
Charging connector contamination (Type-C/Micro-USB)
One of the most common reasons why the phone charges slowly is the banal dust and pile in your pockets. Over time, the USB connector is stuffed with compacted dirt that prevents the cable from entering the end. Contacts do not close tightly, and the phone cannot "agree" with the charger to turn on the fast charging mode.
You may not see it visually, you need to look carefully at the port in good light, if you see a gray plaque or villi inside, you need to remove them carefully, and a wooden toothpick or a plastic spatula is perfect for that.
Do not use metal needles or pins under any circumstances! you can close contacts at the bottom of the connector or damage the central tongue, resulting in short circuits and expensive repairs.
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Use compressed air or a soft brush to clean the connector to avoid mechanical damage to the contacts inside the port.
Programmatic failures and background processes
Often the problem is not hardware, but software. If your Redmi Note has a lot of heavy apps running, navigation or downloading large files, the battery runs at almost the same rate as it charges, creating the illusion of slow charging.
In addition, MIUI can have errors that block the charge controller from working properly, and a driver failure or update conflict can cause the phone to “forget” how to handle native charging at full power.
Check the battery usage statistics in the settings. If you see an application that consumes a lot of power in the background while the screen is off, that could be the reason. It's also worth checking if the power saving mode is on, which artificially limits the charge current to extend the battery life.
- 📱 Close all running applications before setting up for charging.
- 🔌 Reboot your smartphone to reset temporary system errors.
- 🔋 Turn off the “Energy Saving” mode during charging.
- 📶 Turn off Wi-Fi and Bluetooth if they are not in use.
Effect of temperature on charge speed
The lithium polymer batteries used by Xiaomi are very sensitive to temperature. If you charge your phone in a hot room, in direct sunlight, or while playing, the protection system automatically reduces the charge current.
This is necessary to prevent overheating and possible battery bloating. At temperatures above 40-45 degrees Celsius, fast charging can completely shut down, and the phone will switch to minimal currents (0.5-1 Amps).
The same thing happens in the cold, if you bring your phone outdoors into the heat, let it warm to room temperature before you plug it in, and charging a cold battery can cause it to degrade permanently.
Optimal temperature conditions
Battery wear and its impact
Over time, battery capacity drops and internal resistance rises. The old battery simply cannot take in a large current of charge without the risk of overheating. The Power Management System (BMS) reads the state of the cell and limits the incoming power to protect the device.
If your smartphone is already 2-3 years of active use, slowing down charging is a natural aging process of a chemical current source, in which case it will not be possible to speed up the process programmatically, only replacing the battery will help.
You can check the battery status using an engineering menu or third-party apps like AccuBattery or AIDA64, and note the "State" or "Health" setting, if it's below 80%, it's time to change the battery.
| Battery status | Description | Recommended action |
|---|---|---|
| 90–100% | New or almost new battery | Keep up, keep track of the cycles. |
| 80–89% | Normal wear and tear | Continue to use, there may be a slight loss of work time. |
| 70–79% | Critical wear and tear | Replacement is recommended, the phone can turn off in the cold |
| Less than 70% | Emergency state | Urgent replacement to avoid bloating |
Resetting and calibration
Sometimes the charge controller forgets the actual limits of the battery capacity, and in this case, the calibration procedure helps, allowing the system to re-determine the 0% and 100% charge points, which can correct the incorrect display and improve the charging algorithms.
To perform the calibration, discharge the phone until it is completely turned off. Then, without turning it on, charge to 100%. After the indicator shows full charge, hold on charging for another 1-2 hours. Then perform a full reboot.
☑️ Checklist of diagnostics
If the software methods don't work, you can try resetting to factory settings, which will delete all applications and data, but return the system to its original state, eliminating software conflicts. Remember to back up important data before doing so.
⚠️ Before performing a full reset, be sure to save all important photos, contacts and documents to the cloud or computer, as the internal memory will be completely cleared.
When is the time to contact the service
There are situations where self-repair is impossible or dangerous, if you've tried all the cables, cleaned the connector, reset, but the charging speed hasn't changed, the problem is deeper, it could be a malfunction of the power controller, the plume, or the motherboard itself.
The alarm is also a bloating battery, and if the back of the phone starts to move away or the screen blows out, you can't use it, and that's a direct fire safety threat.
It is also worth contacting the service if the phone is only charging in a certain position of the cable, which indicates mechanical damage to the charging socket, which requires soldering and replacement of the component.
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If replacing the cable and cleaning the connector did not help, and the phone is warming or swelling - immediately stop charging and contact the specialists.