Laptop / Charger Wattage Compatibility

Can I charge my laptop with a charger that has lower wattage than the original?

Yes, but with limitations. A lower-wattage USB-C charger will charge your laptop when idle or in sleep mode, but may not keep up with power demand during heavy tasks — the battery will drain slowly even while plugged in. For example, a 65W charger on a laptop rated for 130W will typically charge at roughly 30 to 50 percent of normal speed under load. For sustained full-performance work, use a charger at or above the laptop's rated wattage.

What is USB Power Delivery and does my cable matter?

USB Power Delivery (USB-PD) is the standard that allows USB-C chargers and devices to negotiate voltage and current. A charger marked USB-PD can deliver from 15W to 240W depending on what the device requests. Critically, your USB-C cable must also support the wattage you need — a cable rated for 60W will cap charging speed at 60W even if the charger and laptop both support 100W. Use a cable explicitly rated for the wattage your charger delivers, and check for the wattage marking printed on the cable itself.

Are third-party laptop chargers safe to use?

Reputable third-party USB-C chargers that carry UL or CE certification and support USB-PD are generally safe. Risks come from uncertified chargers that may not regulate voltage correctly, causing slow charging, overheating, or rare damage to the battery management system. Barrel-connector chargers (proprietary plugs) carry higher third-party risk because they bypass USB-PD negotiation entirely. Always check for a safety certification mark before using a non-OEM charger.