Start with the charger that came with your device

The charger bundled with your phone, laptop, or tablet is designed for that specific device's battery. It delivers the right voltage and current — the two things that determine whether charging helps or harms your battery over time. Using a different charger, even one that physically fits, can push too much power into the battery too fast, or deliver power unevenly, and both shorten battery life.

If you have lost the original charger, buy a replacement from the device maker or from a seller with a clear return policy. Third-party chargers vary wildly in quality. A cheap charger might work today and damage your battery tomorrow in ways you won't notice until the battery fails months from now.

Key Takeaways

  • Use the charger that came with your device, or buy a replacement from the manufacturer, because mismatched chargers can damage the battery even if they physically fit.
  • Charge when the battery drops to 20 percent rather than waiting until it dies, because deep discharges wear out lithium batteries faster.
  • Unplug as soon as the battery reaches 100 percent, because leaving a phone plugged in overnight keeps the battery in a high-stress state.
  • Keep your device cool while charging — remove thick cases, charge in a cool room, and avoid charging in direct sunlight or in a hot car.
  • Fast charging and wireless charging are convenient but generate more heat, so use them only when you need the speed, not as your daily routine.

Charge before the battery fully drains

Lithium batteries — the kind in nearly all phones, tablets, and laptops — wear out faster when you let them drop to zero. Each time a battery fully discharges, it loses a small amount of capacity that never comes back. Over a year, letting your battery die regularly can reduce its total capacity by 10 to 20 percent.

Plug in when the battery reaches 20 percent. You do not have to wait for a warning. If you charge at 20 percent instead of 5 percent, your battery will last noticeably longer over the course of a year. If you can charge even more often — say, at 30 or 40 percent — the battery will last even longer, though the difference becomes smaller with each charge.

Unplug when the battery reaches 100 percent

Leaving a phone or laptop plugged in after it reaches full charge keeps the battery in a high-stress state. The charger stops pushing current, but the battery sits at maximum voltage, which slowly degrades the chemical compounds inside. Overnight charging — plugging in before bed and leaving the device plugged in all night — is one of the fastest ways to wear out a battery.

Set a phone alarm or a calendar reminder to unplug after one to two hours of charging. If you charge overnight because of your schedule, that is a real constraint, but know that you are trading battery lifespan for convenience. Some newer phones and laptops have a "charge limit" setting that stops charging at 80 percent; if your device has this option, turning it on for overnight charging will extend battery life.

Keep the device cool while charging

Heat is the enemy of lithium batteries. Charging generates heat, and a hot battery degrades much faster than a cool one. A battery that charges at room temperature will last significantly longer than one that charges in a warm environment.

Remove thick phone cases before charging if the case traps heat. Charge in a cool room rather than in direct sunlight or in a parked car. If your device gets warm to the touch during charging, unplug it and let it cool for 15 minutes before plugging back in. Laptops generate more heat than phones; if your laptop is hot while charging, place it on a hard, flat surface rather than on a bed or pillow, which blocks airflow underneath.

Use fast charging and wireless charging sparingly

Fast charging pushes more power into the battery in less time, which generates more heat and stresses the battery more than standard charging. Wireless charging also generates extra heat because energy is lost as it transfers through the air. Both are convenient, but both wear out the battery faster than a standard wired charger.

Use fast charging when you need the speed — before leaving the house, or when you have 30 minutes and need to reach 50 percent. Use it as your daily routine, and your battery will noticeably degrade within a year. For everyday charging, especially overnight, use the standard charger that came with your device.

What to do if your charger stops working

A charger that no longer charges, or charges very slowly, is usually damaged at the connector — the part that plugs into your device. Dirt, lint, or bent metal inside the port can also block the connection. Before buying a new charger, clean the port on your device with a dry cotton swab or a soft brush. Do not use water or metal objects.

If cleaning does not work, the charger itself is likely damaged. Buy a replacement from the device maker. If you buy a third-party charger, look for one that explicitly states it is designed for your device model, and check the reviews for mentions of overheating or slow charging. A charger that costs half the price of the original is often half the quality.

Charging in cold weather

Lithium batteries do not charge well in cold temperatures. If you bring a phone inside from freezing weather, the battery may refuse to charge until it warms up. This is normal and not dangerous — the battery is protecting itself. Let the device sit at room temperature for 30 minutes before plugging it in.

Do not try to charge a cold battery by wrapping it in blankets or putting it in a warm place. The battery will warm up on its own. Forcing heat into a cold battery can damage it. Once the device reaches room temperature, charging will work normally.

Frequently Asked Questions

Is it bad to charge my phone every night?

Charging overnight keeps the battery at 100 percent for hours, which degrades it faster than daytime charging. If you must charge overnight, use a charger with a lower wattage if available, or enable a charge limit setting if your phone has one. The battery will still degrade, but more slowly.

Can I use a charger from a different brand if it fits?

Physical fit does not mean electrical match. A charger from a different brand may deliver the wrong voltage or current, damaging the battery even if it charges the device today. Stick with the original charger or a replacement from the device maker.

Why does my phone get hot while charging?

Some heat during charging is normal, but excessive heat means the charger, the battery, or the device itself is stressed. Unplug when ready, remove any case, and let it cool. If it stays hot even with a standard charger in a cool room, the battery may be failing and should be replaced.

Is wireless charging worse for the battery than wired charging?

Wireless charging generates more heat than wired charging, so the battery degrades slightly faster. If you use wireless charging daily, the battery will not last as long as if you used a standard wired charger. Use wireless charging for convenience when you need it, not as your primary charging method.

What should I do if my device won't charge at all?

First, clean the charging port with a dry cotton swab. If that does not work, try a different charger if you have one. If the device still will not charge, the battery or the charging circuit inside the device may be damaged and needs professional repair or replacement.