Phone not charging or charging slowly: cable, port and settings

Unplug the charger and switch the device off. Never puncture, bend or heat a swollen battery.

Do not plug in a cable if the charging port is wet or you suspect there is liquid inside it.

Samsung sums up four sources of trouble: a high device temperature, charging accessories, charging settings, and debris inside the port. Apple gives a similar list for accessory alerts on the iPhone: a dirty or damaged port, a defective charging accessory, or a USB charger that was not designed to charge devices.

In other words, the battery is rarely the first suspect. Work through the checks starting with the easiest: charger and cable, the outlet, the port, moisture warnings, then the battery settings. Try charging again after each step, as Apple suggests, so you know which step solved the problem.

1. Inspect the whole cable and the charger head. Apple asks you not to use accessories with signs of breakage or bent prongs, and Samsung says to stop using a broken or peeling cable right away.
2. Unplug the cable and plug it back in firmly. According to Samsung, the cable should fit the port snugly, not loosely.
3. Try another genuine adapter and cable. To test the accessories, charge a different device with the same adapter and cable.
4. Charge from a wall outlet, not from a laptop or a PC. Samsung writes that fast charging does not work when the phone is connected to a PC or a standard USB device.
5. Check that the outlet works (Google suggests plugging in a lamp), or switch to another outlet.

In many Indonesian homes, chargers are plugged into an extension cord or a multi-outlet adapter. If charging acts up, plug the charger straight into the wall outlet, as Apple suggests; that also rules out a loose connection in the adapter.

Charger wattage matters too. The iPhone User Guide says charging can take longer with a wired charger that delivers 7.5 watt or less, or a wireless charger under 10 watt. Google recommends a PD adapter of at least 15 W for a Pixel, and a 30 W PPS adapter for faster charging.

Samsung lists dust and lint inside the port among the most common causes. Built-up debris stops the end of the cable from touching the charging terminal properly, so the phone charges on and off or not at all. A phone that often rides in a pants pocket or a bag collects this kind of lint more easily.

Samsung's steps: turn the phone off, look into the port with a flashlight, then gently blow out any dust or debris near the metal terminals. Do not dig into the port with a safety pin, a needle or another metal object. Samsung names metal particles in the connector as one of the things that make a phone heat up while charging.

If the port looks completely blocked, or the debris does not come out by blowing, Samsung asks you to get help from the nearest service center. Cleaning any deeper than that risks damaging the terminals inside the port.

Galaxy phones with an IP68 water-resistance rating or higher have a moisture sensor in the USB port. When the sensor detects moisture, a water drop icon appears and wired charging stops to prevent corrosion. Samsung writes that the warning can appear even if the phone never touched water, because very humid air can trigger it too.

Indonesia's humid climate, the rainy season, and the habit of charging in the kitchen or the bathroom make this warning fairly common. Samsung's steps: unplug the charger, wipe the phone with a dry cloth, gently shake it with the port facing down, then leave it in a well-ventilated place or dry it with a fan. Once the port is completely dry, restart the phone and charge it again.

If the icon only appears with one cable, that cable may be the damp one, so try another cable. For the iPhone, Apple gives a firm warning: if you suspect there is liquid in the charging port, do not plug the charging cable in.

Charging that stops is not always a fault. On a Galaxy, Battery protection can stop charging early or cap the maximum charge level. Check it under Settings, Battery, Battery protection, then pick another option or turn it off. For slow charging, open Settings, Battery, Charging settings, then turn on Fast charging. On some older versions this menu sits under Battery and device care.

On an iPhone, charging runs fast up to about 80%, then slows down to reduce stress on the battery and limit the temperature. Optimized Battery Charging can also delay charging past 80% until shortly before you usually use the phone. On iPhone 15 and later, also check whether a charge limit is set.

Temperature plays a part as well. Samsung and Apple both write that charging can pause or slow down when the phone is too hot, then resume once it cools. Move the phone and the charger somewhere cooler before you conclude that something is broken.

A phone with a completely empty battery can look dead even while it charges. The iPhone User Guide says the screen may show nothing for up to 2 minutes before a low-battery image appears. Google writes that a Pixel whose battery is fully drained and has not been turned on for a long time may not respond for up to 25 minutes after it is plugged in.

Leave the phone charging with a charger, cable and outlet that are known to work. Apple suggests waiting half an hour, then forcing a restart if the screen is still dark. On iPhone 8 or later, press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the side button until the Apple logo appears. On a Pixel, press and hold the power button for 5 to 7 seconds.

Take the phone to the authorized service center for its brand if:

• it still won't charge with another genuine charger and cable from a working outlet;
• the port looks loose, bent or corroded, or stays blocked after you blow it out;
• the moisture warning does not go away even though the phone and the cable are completely dry;
• the phone or the charger gets very hot, you smell burning, or the phone body looks swollen;
• the battery runs down much faster than before, which Samsung says can point to a hardware problem.

Replacing a port or a battery is a job for a service center technician. Opening the battery pack or replacing the battery cells is not something to do at home. Apple writes that the iPhone battery should only be serviced by Apple or an Apple Authorized Service Provider. Back up your data before you hand the phone in, as long as it still turns on.