This is for anyone who owns a MacBook Air or MacBook Pro with a USB-C or MagSafe charging port and needs a spare charger, or whose Mac charges slowly. You will learn how to read the watts on your original adapter, what a different wattage does, what USB-PD means, how to pick a cable, and which checks to run before paying for a spare.
Which USB-C charger wattage suits my MacBook?
Short answer: Use the wattage printed on the charger that came with your MacBook. A charger with the same or a higher wattage that supports USB-PD is fine. A lower-watt charger may charge slowly, or may not keep up while you work. Apple's specifications page for your exact model also lists the adapter that comes with it.
How do I find the wattage on my original adapter?
- Unplug the adapter and look at the small print on the body, near the plug pins or on the underside.
- Find the line that gives a number followed by W, for example the watts the adapter can supply.
- Also note the output line, which shows volts and amps. Higher watts means more charging power.
This guide is about USB-C charging. Older MacBooks with a non-USB-C MagSafe port use Apple's own adapter, so match that exact adapter instead.
If the print is worn away, check the Apple specifications page for your MacBook model. The model name is under the Apple menu, then About This Mac. The wording can differ slightly between macOS versions.
What happens with a lower-watt or higher-watt charger?
A MacBook under heavy work, such as video editing or many browser tabs, can draw more power than a small phone charger offers. The result is a charge level that rises very slowly or even drops while plugged in.
What does USB-PD mean?
USB-PD (USB Power Delivery) is a standard in which the charger and the laptop talk to each other and agree a safe voltage and current. A proper USB-PD charger will not push more than the laptop asks for, so a bigger charger does not harm a MacBook. Look for USB-PD printed on the charger or its box.
Which cable do I need?
The cable matters as much as the charger. A thin phone-charging cable may carry only a limited amount of power. For laptops, look for a USB-C cable marked for the wattage you need, such as 60W or 100W, and ideally a good brand. Our guide to the best USB-C cables for fast charging explains what to look for. A damaged or frayed cable should be thrown away, not taped.
Checks before you buy a spare
- Note the original wattage and your MacBook model.
- Choose a charger with the same or higher wattage and USB-PD.
- Buy from a seller who accepts returns, and check the printed markings are clear and sharp.
- Be cautious about very cheap chargers sold without a brand.
- Test: plug in, and watch the battery icon rise while the laptop is in use.
Can I charge a MacBook from a power bank or monitor?
Sometimes, but only if the power bank or monitor supplies enough watts through USB-PD. A small power bank may keep the MacBook alive while it sleeps and still lose ground when you work. Treat it as an emergency top-up, not a daily charger, and read its wattage label before relying on it.
Heat, humidity and unstable power in India
Voltage swings can stress a poor charger. A surge-protected extension board helps, and so does a UPS (a small battery backup box) for desk setups. In the monsoon months, keep the charger and the port dry. If a charger or cable feels very hot, smells burnt, or sparks, stop using it at once.
When to get help
- A new, correct charger still charges slowly or not at all.
- The port feels loose, the cable wobbles, or the plug is discoloured.
- The MacBook shows Not Charging while plugged in.
- The battery drains quickly even on a good charger.
Our Apple MacBook charger page and the Apple repair hub cover chargers, ports and batteries. A MacBook still under Apple warranty should go to Apple's authorised service first. We repair MacBooks out of warranty or when the owner chooses independent repair, by courier from anywhere in India, and with doorstep service in Hyderabad via our Apple service page for Secunderabad. The exact quote comes after diagnosis. ₹149 doorstep visit fee, waived when you approve laptop repair with us.
A note from the LRW Engineer Team
Keep the original charger as your reference and treat a spare as a convenience, not a gamble. If a spare charges badly, do not assume the MacBook is at fault. Try the original charger on a different socket first. That one test separates a charger problem from a port or battery problem. For wider help, read our charger troubleshooting guide.