Phone Won't Charge, or Charging Slowly? Here's How to Fix It (iPhone & Android)

You plug your phone in overnight and wake up to a dead or barely-charged battery — or it charges so slowly it can't keep up with a day's use. It's an alarming feeling, because a phone you can't charge is a phone that's about to become a paperweight. But here's the reassuring part: a genuinely dead battery is near the bottom of the list of causes. Far more often it's a worn-out cable, a charging port packed with pocket lint, a "liquid detected" warning that's blocking the charge on purpose, or a charger that's too weak to fast-charge your model. All of those are free or cheap to sort out, and you can work through them in a few minutes before spending anything. This guide covers iPhone and Android, since the causes — and the order to check them in — are nearly identical.

Start here: is it the cable, the charger, or the phone?

The single most useful thing you can do is figure out which part is actually failing, and you do it by swapping one piece at a time. Cables are the number-one culprit — they get bent, yanked, and frayed where the cord meets the connector, and a cable can look perfectly fine while a broken wire inside has killed it. So try a different cable first. Then try a different wall adapter (the "brick"), and a different wall outlet — not a USB port on a power strip, a TV, or a laptop, which often don't push enough power. If you have another Apple or USB-C charger in the house, or can borrow one, use it. A surprising share of "my phone won't charge" problems end right here, with a $10 cable.

There's one clever test that isolates the phone's charging port specifically: if you have a wireless charger (or can borrow one, or use a friend's), set the phone on it. If the phone charges wirelessly but refuses to charge with any cable, the battery and the phone are fine — the problem is the cable or the physical port, not the phone's ability to charge. If it won't charge wirelessly either and you've tried a couple of known-good cables and bricks, that points more toward the battery, the phone's software, or a deeper fault, covered further down.

The most overlooked cause: lint packed in the charging port

This is the fix that fixes the most phones and that almost nobody checks. Your phone lives in a pocket or a bag, and the charging port is a tiny open slot that collects lint, dust, and pocket fuzz all day long. Over months it compacts into a dense little plug at the bottom of the port, and once it builds up enough, the cable physically can't seat far enough to make contact — so it either won't charge at all, or only charges when you hold the cable at a certain angle or press it in hard. If your cable feels like it doesn't click in as deeply as it used to, this is almost certainly your problem.

To check, shine a bright light straight into the port and look closely — you'll often see a grey wad of lint sitting against the metal contacts. To clean it, power the phone off first, then gently pick the debris out with something thin and non-metal: a wooden or plastic toothpick, or a clean, dry anti-static brush, works well. Be patient and gentle — the little contacts inside are delicate, and the firm rule is never use anything metal (no pins, needles, or paperclips), which can short the pins or scratch the contacts. Don't squirt anything wet in there. A can of compressed air can help loosen it if you're nervous about poking around. People are genuinely surprised how much lint comes out, and how often the phone charges perfectly the moment it's clean.

The "Liquid Detected" or moisture warning that blocks charging on purpose

If your phone flashes a warning when you plug in — an iPhone says "Liquid Detected in Lightning/USB-C Connector" and Samsung and other Android phones show a little water-drop icon — then your phone is refusing to charge on purpose, as a safety feature. It has sensed moisture in the port, and it won't let current flow until things dry out, because charging a wet port can corrode the contacts or damage the phone. This catches people out badly: the phone looks broken, but it's actually protecting itself, and it'll charge fine again once it's dry. It doesn't even take a dunk — a steamy bathroom, a sweaty gym pocket, rain, or just humid weather can trigger it, and sometimes it's a false alarm from a damp cable rather than the phone.

The fix is to dry it, not to fight it. Unplug the cable. Hold the phone with the port facing down and tap it gently against your hand to shake out loose droplets, then leave it somewhere dry with a bit of airflow — a fan pointed at it is ideal. Give it at least 30 minutes before trying again; a thorough dry can take several hours, occasionally up to a day. If you need power in the meantime, charge it wirelessly (wipe the back dry first) — the moisture sensor only blocks the port, not the wireless coil. A few things are important to get right here, because the popular "fixes" cause real damage: don't stick a cotton swab, paper towel, or anything else into the port (it leaves fibres and pushes moisture deeper), don't blast it with a hairdryer or other external heat or compressed air, and don't bury it in a bag of rice — rice does little and its dust and starch can get into the port. On an iPhone, resist repeatedly tapping the "Emergency Override" that sometimes appears; forcing the charge while it's genuinely wet is exactly what the warning is trying to prevent. If the warning keeps coming back on a phone you know is bone dry, try a different cable first, and if it still nags, the port may have lint or early corrosion that needs a proper look.

It charges, but painfully slowly

Slow charging is usually a charger problem, not a phone problem. Modern phones fast-charge only when the charger can deliver enough power in the right way, and a lot of cheap or old bricks simply can't. On an iPhone, if you go to Settings > Battery and see a "Slow Charger" note, that's the phone telling you the charger isn't up to it — for fast wired charging on an iPhone 15 or later you want a USB-C Power Delivery charger and a USB-C cable. Samsung and other Androids are fussier still: their "Fast" and "Super Fast" charging need a charger that supports USB Power Delivery with PPS and enough wattage for your model, and a cable rated to carry it. Off-brand bricks that leave those out will only ever trickle-charge. It's also worth checking that fast charging is actually switched on — on Samsung it lives under Settings > Battery (on some models Settings > Battery and device care > Battery), where you can turn on Fast charging, Super fast charging, and Fast wireless charging.

A couple of other things quietly slow a charge. Using the phone hard while it charges — gaming, navigation, video calls — generates heat, and a hot phone deliberately charges slower to protect the battery (charging in a hot car or in direct desert sun does the same; move it somewhere cooler). And modern phones intentionally slow the last stretch: features like the iPhone's Optimized Battery Charging hold at 80% and finish later to spare the battery, and iPhone 15 and newer models have an optional charge limit that stops at 80% on purpose. If your phone pauses at 80% and finishes just before your alarm, that's a feature working as intended, not a fault — you can change it in Settings > Battery if you'd rather it always fill up.

Don't skip the software side: restart and update

Sometimes the phone isn't failing to charge — it's frozen, and a frozen phone with a black screen looks identical to a dead one. A forced restart wakes it up and clears a surprising number of charging and power glitches, and it costs nothing. On an iPhone (8 and later), press and quickly release Volume Up, press and quickly release Volume Down, then press and hold the Side button until the Apple logo appears — keep holding past the "slide to power off" screen. On most Android phones, press and hold the Power and Volume Down buttons together for about 10 seconds until it restarts (some Pixels need the Power button held for around 30 seconds). Leave it plugged into a known-good charger while you do this, and give it a few minutes — a totally drained battery sometimes needs 10–15 minutes on the charger before the screen will even light up.

If the phone does charge but the battery behaves strangely — drains absurdly fast, jumps from 40% to dead, or won't go past a certain percentage — install any pending software update (iPhone: Settings > General > Software Update; Android: Settings > System > Software update), because battery-management bugs are a common thing those updates fix. A restart plus an update clears the software causes; if the trouble survives both, you're into hardware.

When it really is the battery or the port

If you've tried known-good cables and chargers, cleaned the port, ruled out a moisture warning, and restarted, and it still won't charge or hold a charge, the problem is physical — and the two usual suspects are the battery and the port. A worn-out battery shows itself in a pattern: the phone charges but drains unusually fast, dies at 20–30% and shuts off, or won't climb past a certain level. You can check the battery's health on an iPhone under Settings > Battery > Battery Health & Charging (a Maximum Capacity well below 80% means the battery is near the end of its life); many Samsung phones show a battery diagnostic in Settings > Battery and device care or the Samsung Members app. A battery replacement is a common, affordable repair that makes an otherwise-good phone feel new again.

A worn charging port shows itself differently: the cable feels loose or wobbly, the phone only charges if you wiggle or prop the cable at a particular angle, or it charges intermittently. If you've already cleaned out the lint and it's still flaky, the port's contacts or solder are worn or damaged, and that's a repair rather than a DIY fix. Two situations deserve a flag of their own. If the back of the phone is bulging, the screen is being pushed up, or the phone won't sit flat, the battery is swollen — stop charging it and stop using it, because a swollen lithium battery is a fire and injury risk and needs professional replacement, not a poke. And if the phone stopped charging right after it got wet or took a hard drop, treat it as liquid or impact damage to the port or board, which is worth having looked at before corrosion spreads.

When to bring it in

The honest truth is that most "my phone won't charge" cases are solved at home for the price of a new cable or two minutes of cleaning lint out of the port — so work through the cheap, free steps above before you assume the worst. Where it's worth handing over is when the battery health has clearly dropped, when a cleaned port is still loose or intermittent (a port repair is fiddly micro-soldering on most phones), when there's a swollen battery, or when the phone got wet or dropped and hasn't charged since. We replace phone batteries and charging ports, clean and assess water-damaged ports, and sort out the software side, for iPhone and Android, across Southern California and the Coachella Valley — in person or by remote support. And because we don't make our money selling you a new phone, we'll tell you honestly when a $10 cable or a clean port was all it ever needed.