At the present time of charging, the mobile phone isn't really like in the past as with the new advanced technologies. Such quick chargers will also charge your device full within 1-2 hours.
In case your device supports a fast charger, and you still do it, but it takes too much time for your device to be fully charged. Then you don't need to worry, as we're here to discuss a few suggestions with you if your device is charging slowly.
1. There are also situations where your Charger Adapter or Data cord has the default cord, but not with your device. It is best to still use the original plug and cable to power your device, so if the original battery adapter or data cable is defective or not functioning, you must visit the official store or repair center of the framework and purchase the original data cable or adapter from there. As in most situations, it doesn't seem like we often use cables or connectors that aren't original and have a really negative effect on our smartphones.
2. It's not always a data cable or adapter problem, because there are certain occasions where the device is gradually charging because of the source of power. Unless you are using a wireless charger then it is probably time to turn to wired chargers as wireless chargers, charge the unit slower than the wired chargers.
3. It is not appropriate for the smartphone to charge gradually because of the hardware. If the device is not updated, there is a good chance that your device will take a lot of time to charge than before, so it is advisable to update your device's software. Even, I've seen some glitches myself like we're downloading an update, and all of a sudden, there's an issue with the phone charging slow or any other issue. So make sure you uninstall the specific app if you're having any kind of problem.
4. Even after you've followed every possible resolution your smartphone is still charging slowly, there's a lot of chance that your device's USB port will be defective. As you've been using your smartphone for some time, the USB ports get stuffed with sawdust and the USB ports get weakened. It is therefore advisable to clean USB ports (From experts). But even after cleaning USB ports, you still face the issue of slow charging, and there is a lot of risks that the USB port of your device will be broken and you need to repair it.
5. Even after following the above steps, you are still confronted with a slow charging problem. It is recommended that you visit the closest service center and test the battery of your device. And there are several occasions where the battery is running, but because of an engineering error, the battery is slowly charging.