Why a phone doesn't chargeThe problem occurs in various guises. Either your phone won't charge AT ALL when it is plugged in, or it only charges very slowly (sometimes barely faster than it is discharging). It’s a very common complaint, and one I’ve suffered from with devices myself, so here are a few solutions.
DIY USB port fixThe quickest, easiest, and often most successful solution, is to do a little DIY repair on your actual hardware. The problem is often that the metallic surfaces inside the USB port and the microUSB charger are not making good contact, either through a manufacturing defect or because of the continual plugging and unplugging of the charging cable.
All you need to do is shut down your device, remove the battery if possible and use something small, like a toothpick, to 'lever up' the little tab inside the USB port on your smartphone or tablet. Do so very carefully and gently, then reinsert your battery and plug it in again. Nine times out of 10 this is all that is required.
Do you keep your phone in the pocket of your jeans? If so, lint could be the culprit: we've lost track of the number of times the reason for unreliable USB charging turned out to be lint from our Levis. We've seen phones whose charging port ended up choked with chocolate after being chucked in a handbag alongside a packet of kids' sweets. A can of compressed air can blow out the offending irritants and get your USB connection back to normal.
Switch cablesThe flimsiest part of a charger is the cable, not the adapter that plugs into the wall socket. Apple users are particularly vulnerable here, because Apple's proprietary and expensive Lightning cables appear to have a life expectancy of around 15 minutes. But all cables have a tough life, and endless flexing and curling can take its toll.
The easiest way to diagnose a faulty cable is to try a different one and see if it works properly with your device. If it does, it's new cable time; if it doesn't, that's another potential villain we've ruled out.
If the cable doesn't seem to be the problem, check the wall plug adapter — especially if it's one whose charging cable can be removed. We've encountered issues in multiple chargers where the USB port becomes a little loose after endlessly plugging and unplugging it. Also, ensure that the same charger/cable combination works on a different device, as this will help you eliminate the possibility that it is your device at fault, rather than the cable or charger.
Safety firstDon't charge your phone near water or in excessively hot or humid conditions. Also, do not overcharge your device; charging overnight when your battery only needs two or three hours is a bad idea, and can lead to a battery exploding or damaging your phone. Your phone has a cut-off switch for your battery, but sometimes this doesn't work. It's better to be safe than sorry. Or burnt to a crisp.
If you're replacing a charger or cable, be wary: the internet is stuffed with reports of cheap third-party chargers that went bang in the middle of the night or turned smartphones into toast. As with any electrical equipment, make sure that anything you buy complies with all the relevant safety standards. A super cheap eBay offering from an obscure Chinese supplier might not.
Replace the batteryBatteries don't last forever, and after a couple of years they start to struggle to hold a charge. The more often you discharge and recharge them, the sooner they'll need replaced — although if your battery's stuffed after just six months, it's probably faulty and you should make a warranty claim for a free replacement. But if the battery's older than two or three years, it's probably approaching the end of its lifespan.
Some defective batteries are easy to spot, because they start to bulge or leak fluid. If nothing like that is obvious from the outside, remove your device's cover and inspect the battery (if you can; some devices have sealed battery compartments). If the cover doesn't come off, you could try laying the device on its back and spinning it. A bulging battery will deform the case — you might not be able to see this bulge, but it might be enough to allow your phone to spin. This obviously doesn't apply if the back of the device is supposed to be curved!
If you decide the battery is damaged and you're not covered by a warranty, it's time to replace it with a manufacturer original or a respected third-party unit. Don't just go online and find the cheapest battery you can: in our experience really cheap third-party batteries are often more trouble than they're worth, and by 'trouble' we mean 'explodey'. We'd strongly advise you to stick with reputable brands.
Different chargers charge differentlyCharging from a wall socket will always charge faster than via PC or laptop, because computers' USB ports don't deliver very much power. A wall socket can deliver twice as much power than a USB port can, and in the case of fast chargers it can deliver as much as five times the power — which means much, much faster recharging.
If your charger doesn't appear to be delivering the goods, check that it's the right one. A charger from another device might not deliver the right amount of juice — for example, a charger for a Bluetooth headset won't put out as much power as one designed specifically for smartphones. In the case of recent high-end phones, you might have a phone that supports fast charging but a charger that doesn't deliver it.
Update or rollbackSoftware updates and new Android versions can play havoc with your battery life, especially when upgrading an old device to current software. Newer devices are often optimized to take advantage of the latest software, packing bigger batteries and pre-optimized hardware, whereas your two-year-old device can struggle when it makes the jump from behind the pack.
If this happens to you, consider rolling the device back to an earlier Android version, though be warned that this carries security risks. (The latest software versions are always recommended to keep your device protected, and while the risk of keeping your smartphone on an older version is often negligible, it’s worth noting.)
Similarly, sometimes device battery life can be significantly improved thanks to an update, as seen with the Moto 360 smartwatch, so if you think you might be way behind on your Android software version, head to the 'about device' page in your settings and check for an update.
Switch it offUsing battery intensive apps/features while you are charging your device will affect how fast it gains battery life. If you are charging while Skyping somebody at full screen brightness, the device will naturally take longer to charge than if it is locked with Wi-Fi and 4G turned off. Switch the device onto airplane mode, or off completely, when you are charging if you want to see the fastest energy injection. Think of it as giving your device a power nap. Or a red bull. In the dark.
Calibrate your batterySometimes what your device 'thinks' your battery life is can differ to what it actually is. The effect of this is that your phone may function differently based on the estimated battery life, such turning off before it is actually out of juice or taking an hour to chew through the last 2 percent.
We’ve already written an extensive guide on how to calibrate your smartphone battery on an Android device, so I won’t retype it all here, but this is a useful option to try before completely ditching your defunct power pack.
Try these steps on how to fix a phone that won't charge first before replacing the battery.
If all else fails, just double check that you actually have the power point switched on. That is the first thing they will ask you if you call your manufacturer for help, which might need to be your next step if none of these solutions have worked for you!
Have you suffered from a smartphone that won't charge properly? Let us know if you've found a fix that we haven't mentioned here in the comments.