Why Xiaomi Redmi 8’s phone is charging for a long time: a full analysis

Owners of the popular Xiaomi Redmi 8 budget smartphone often face a situation where battery power is taking an unnecessarily long time to replenish, which is annoying, especially when you need to get out of the house urgently and the device is barely 30 percent. The problem can be hidden in both software failures and physical wear of components. Understanding the root cause is the key to a quick solution.

In this article, we will take a look at all the possible factors that affect the charging speed of your gadget, learn how to distinguish between the normal behavior of a lithium polymer battery and the signs of a malfunction, and look at system settings, the state of the charging cable, and the effect of background processes on energy consumption during connection to the grid.

If a smartphone that used to charge in an hour and a half now spends the night at the outlet, that's a diagnostic signal. The critical threshold is charging time of more than 4 hours for a 5,000 mAh battery using the original adapter. Let's figure out what's stopping this process in your case.

Analysis of the condition of the charging cable and adapter

The most common but common reason for slow charging is that components are damaged. USB cables that come with smartphones often fail to withstand heavy use. Internal veins can break down, causing current to fall. The power adapter can also lose its rated power over time.

Try using another cable, preferably certified and capable of passing current of at least 2 Amps. Cheap analogues often do not meet the declared characteristics and work only on data transmission or very low current. Also check the Micro-USB connector itself for oxidation or pile.

It is important to use the original power supply or quality analogue with support for Quick Charge technology. If you connect the phone to a computer or a weak unit from an old device, the process will go extremely slowly. The standard adapter for Redmi 8 should give out 10 watts (5V/2A).

• 🔌 Check the cable for visible cavities, inflections or insulation scuffs.
• ⚡ Try charging the device from another power supply with known power.
• 🧹 Clean the charging connector with a soft brush from dust and pocket pile.
• 📏 Make sure the cable is less than 1.5 meters long, as long cables increase resistance.

⚠️ WARNING: Using cheap Chinese adapters without safety certificates can not only lead to slow charging, but also to the failure of the power controller on the motherboard.

Effects of background applications and body temperature

A smartphone is a minicomputer, and while charging, it keeps running. If you have a lot of background, navigation, games, or downloading large files, the battery will charge more slowly. The energy is used to run the processor and screen at the same time as the charge is replenished.

So, you have to pay special attention to temperature, because lithium-ion batteries are sensitive to overheating, and if the phone is hot, the protection system artificially limits the incoming current to prevent swelling or fire, and that's the normal response of the controller, not the breakdown.

Close all heavy applications before charging. Turn off GPS, Bluetooth, and mobile internet if you don't need them. It's best to charge the device when you're off or in flight mode, especially if you want maximum speed. Also remove a thick protective case that can interfere with heat transfer.

Users often notice that the phone charges longer at night than during the day, which may be due to the fact that the house is down at night, or the power-intensive appliances are running, but most often the reason is due to active background synchronizations, which start on schedule.

Diagnostics of the Micro-USB connector

The Redmi 8 is equipped with a Micro-USB connector, which is outdated and less reliable than the modern USB Type-C. The main problem of such a port is the loosening of the central tongue and the accumulation of dirt. Over time, the contact becomes unstable, and the phone goes into low-current mode.

Visually inspect the port in good light. There should be no pressed pile inside, which often gets there from jeans pockets. Carefully, using a wooden toothpick or plastic shovel (not metal!), try to clean the insides of the connector. Metal tools can close contacts and burn the board.

If the cable plug is wobbling when you connect, it might be a broken port on the board, and in this case, it's only a replacement of the socket in the service center that helps, and until you get to the master, you can try to lock the cable in a certain position, but this is a temporary solution.

Software failures and MIUI settings

The MIUI shell installed on the Xiaomi Redmi 8 has many optimization features that sometimes work incorrectly, errors in the system can lead to the charge controller receiving incorrect data about the battery status, and the cause can also be “big” system updates.

Check for firmware updates in Settings → About Phone. Often developers release patches that fix power errors. If the problem occurs after the update, you may want to reset (backup).

Turn on Turbo Charging mode if it's available in your version of the software. It's also worth checking the battery usage statistics. If an application consumes resources even in the background, delete it or limit background activity. Resetting network and Bluetooth settings can also be useful, since constantly searching for a signal puts the battery down.

• 🔄 Restart the device to reset temporary system errors.
• 📉 Turn off animations and live wallpaper, they load the processor.
• 🔋 Activate the energy saving mode during charging.
• 📡 Check if the search for networks is constantly turned on 4G squat.

⚠️ Warning: Do not install third-party charging accelerators from the Play Market. These are often miner viruses or just advertising junk that will slow down the system even further.

Natural wear of the battery

The battery is a consumable. The average life of a modern battery is 500 to 800 full charge-discharge cycles. After that, its capacity drops and internal resistance rises. The Redmi 8 phone came out in 2019, and if you use it from day one, battery wear is quite likely.

When electrolyte chemistry is degraded, the phone can take a long time to show 1%, then quickly jump to 20% and just as quickly discharge. The old battery is always slower to charge because of the physical limitations of chemical reactions. The power controller spares the worn cell by delivering less current.

You can check the wear and tear with an engineering menu or a special application, although they show approximate data: if the battery is swelled (the screen is raised or the back cover is gone), it is dangerous to operate the device, in which case an urgent replacement of the battery is necessary.

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If the phone is over 3 years old and used daily, reducing battery life and increasing charging time is a natural physical process that requires battery replacement.

Engineering menu and battery calibration

Sometimes the charge controller forgets the actual battery capacity and misrepresents the percentages. In this case, calibration helps. Xiaomi devices have an engineering menu available through the code in the call. Type ##6485## to see the technical information.

We're interested in parameter. MB_06 (the state of battery health; and MF_02 (number of charge cycles. If MB_06 It says "Good," so the battery is physically fine, and if you see "Bad" or a number that's well below normal, software calibration won't help.

So for software calibration, discharge the phone until it's completely turned off. Then, without turning it on, charge it and wait until the indicator shows 100%. Then you can turn on the device, which helps the system re-determine the limits of capacity.

Code for logging into the engineering menu: ##6485##


Health parameter: MB_06




Cycle parameter: MF_02




Calibration reset: MF_05 (use with caution)

Don't use deep zero discharge often, which is bad for today's Li-Pol batteries. Try to keep the charge in the range of 20% to 80% for maximum life extension. Constant charging to 100% and discharge to 0% accelerate degradation.

When repairs are needed in the service center

If all of the above methods have failed and the phone still charges unnaturally for a long time, the problem lies deeper: it could be a malfunction of the power controller (circuits on the board), breakage of the tracks or oxidation of the board after moisture hits.

Self-repairing is risky, requires professional equipment to diagnose current consumption, and the wizard will connect the phone to the power supply and see if the current is lost at the port entrance, on the controller or directly in the battery.

Replacing the charge controller is a complex procedure that requires soldering under the microscope. However, it is often cheaper than buying a new smartphone. If the problem is with the board itself, repairs may not be cost-effective for a budget model.

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Before you go to the service, take a screenshot of the purchase check or find a photo of it. Some components may have a warranty, even if the phone itself has already expired.

Frequently Asked Questions (FAQ)