What to do when you don't have your charger

If your charger is lost, broken, or left behind, you have several real options that work right now. A USB cable alone can charge most phones if you have access to a computer, car, or wall outlet with a USB port. Portable battery packs (power banks) are the fastest backup if you own one. If you don't, borrowing a charger from someone with the same phone model, using a public charging station, or charging through a computer are your most practical routes.

The method you choose depends on what you have access to and how quickly you need power. Some options take minutes; others take hours. Some work anywhere; others only work near specific places.

Key Takeaways

  • A USB cable plugged into any computer will charge your phone, even if the computer is off or asleep.
  • Most cars made after 2010 have USB ports in the dashboard or center console that can charge a phone during a drive.
  • Portable battery packs (power banks) are the fastest backup option and can fully charge a phone in one to three hours.
  • Public charging stations in airports, libraries, shopping centers, and transit hubs are free and available during business hours.
  • Borrowing a charger works only if someone nearby has the exact same phone model or a compatible cable.

Charging through a computer or laptop

Any computer with a USB port can charge your phone if you have the right cable. Plug your USB cable into a USB-A port (the flat rectangular port) on the back or side of a desktop computer, or into any USB port on a laptop. The phone will charge even if the computer is off, asleep, or locked — the USB port supplies power as long as the computer is plugged in.

Charging through a computer is slower than using a wall charger. A wall charger typically supplies 5 to 20 watts of power; a USB port on a computer usually supplies 2.5 to 5 watts. This means a full charge takes two to four times longer. If your phone is at 20 percent battery and you need it at 50 percent in 30 minutes, a computer port will not get you there.

The advantage is that you likely have access to a computer at work, school, a library, or a friend's house. Leave the phone plugged in while you work or study, and it will charge in the background.

Using a car USB port or car charger

Most cars built after 2010 have at least one USB port, usually in the dashboard, center console, or on the back of a front seat. Plug your cable into that port while the car is running or the ignition is in the "on" position. The phone will charge at the same speed as a wall charger — roughly 5 watts — so a full charge takes one to two hours of driving.

If your car has no USB port, you can buy a car charger adapter that plugs into the 12-volt outlet (the round socket that used to power cigarette lighters). These cost $10 to $30 and work in almost any car. Plug the adapter in, then plug your cable into the USB port on the adapter.

Car charging is useful if you are driving somewhere and your phone is low. It is not a solution if you are at home or need to charge while parked, because the car must be running or in accessory mode to supply power.

Portable battery packs (power banks)

A portable battery pack, or power bank, is a small device that stores electrical charge and can charge your phone anywhere. They range from $15 to $100 depending on capacity and speed. A basic power bank with 10,000 milliamp-hours (mAh) of capacity will fully charge most phones once. Larger packs with 20,000 mAh or more can charge a phone two or three times.

To use a power bank, charge it fully at a wall outlet first (this takes two to four hours). Then carry it with you. When your phone is low, plug your cable into the power bank instead of a wall outlet. The phone charges at normal speed — one to two hours for a full charge — and the power bank's battery drains instead of your phone's.

Power banks are the fastest backup option if you already own one, because you can charge your phone anywhere without finding an outlet or computer. If you don't own one, buying one takes time and money, so it is not a solution for today's problem.

Public charging stations

Airports, train stations, bus terminals, shopping malls, libraries, and some coffee shops have public charging stations. These are usually wall-mounted kiosks or tables with multiple USB ports and outlets. Plug your cable in and charge for free while you wait.

Charging times vary. If the station has a standard USB port, expect the same speed as a computer port — two to four hours for a full charge. If it has a fast-charging port (labeled "fast charge" or "quick charge"), a full charge takes 45 minutes to 90 minutes.

The downside is that public stations are only available during business hours and only in certain locations. An airport station is open 24 hours; a library station closes when the library closes. You also cannot leave your phone unattended for long periods, because theft is a real risk in public spaces.

Borrowing a charger from someone else

If a friend, family member, or coworker has the same phone model as you, you can borrow their charger. Plug it into a wall outlet and charge normally. This is the fastest option if someone nearby has a compatible charger.

The catch is that chargers are not universal. An iPhone charger will not work with an Android phone. Even among Android phones, older models use micro-USB while newer ones use USB-C. Before you ask to borrow a charger, confirm that the other person's phone uses the same cable type as yours.

If someone has a different phone but the same cable type, their charger may still work. For example, many Android phones use USB-C, so a USB-C charger from a Samsung will charge a Google Pixel. Check the cable connector before you plug in.

What not to do

Some methods people suggest for charging without a charger do not work or are dangerous. Do not try to charge your phone by connecting it directly to a battery, wrapping it in foil, or exposing it to heat. These methods can damage the battery, overheat the phone, or cause a fire.

Do not use a charger that is visibly damaged, frayed, or wet. A damaged charger can short-circuit your phone or cause electrical shock. If you find a charger on the ground or in a public place, do not use it unless you are certain it is safe.

Wireless charging pads (the flat pads you place a phone on) will not work if you do not have one already. You cannot borrow one as easily as a cable, and buying one takes time.

Frequently Asked Questions

Can I charge my phone with a USB cable and nothing else?

No, a cable alone cannot charge a phone. You need a power source — a wall outlet with an adapter, a computer, a car USB port, or a power bank. The cable is just the connector between the phone and the power source.

How long does it take to charge a phone through a computer?

A full charge through a computer USB port typically takes two to four hours, depending on the phone model and the computer's USB version. Newer USB 3.0 ports charge faster than older USB 2.0 ports. Charging is slower than a wall charger because USB ports supply less power.

Is it safe to charge my phone in a car while driving?

Yes, charging through a car USB port is safe while driving. The car's electrical system is designed to handle it. Just make sure the cable is not tangled around the steering wheel or pedals, and keep the phone in a find location so it does not distract you.

What is the difference between a power bank and a regular charger?

A power bank is a portable battery that stores charge and can charge your phone anywhere. A regular charger plugs into a wall outlet and charges your phone directly. Power banks are useful for travel or emergencies, but they must be charged first before they can charge your phone.

Can I use any USB cable to charge my phone?

Most USB cables work with most phones if the connector type matches. An iPhone uses Lightning or USB-C; Android phones use micro-USB or USB-C. As long as the connector fits your phone's port, the cable will charge it, even if it is not the original charger.