Quick Answer
Most Chromebooks charge with a 45W or 65W USB-C Power Delivery charger. Using a lower-wattage charger (like a 18W phone charger) will still charge it, just much more slowly, especially under active use. Higher-wattage chargers than required are safe to use.
Common Causes
Confusion around Chromebook charging usually comes from USB-C being a universal port shape that doesn’t guarantee compatible power delivery, from chargers listing multiple wattages depending on the port used, from generic or off-brand cables not supporting full power delivery, and from the difference between a charger being “compatible” (it charges) versus “optimal” (it charges at full speed).
Fix Steps
Step 1: Find your Chromebook’s original charger rating
Check the label on your original charger, or search your model plus “charger wattage.” Most Chromebooks specify 45W or 65W.
Step 2: Understand USB Power Delivery (USB-PD)
USB-C chargers use the USB-PD standard to negotiate voltage and current with the device. A charger and Chromebook both need to support USB-PD, not just have a USB-C plug, for proper fast charging.
Step 3: Check the cable, not just the charger
Many USB-C cables are charge-only or rated for lower wattages than the charger itself supports. Use the cable that came with the charger, or one explicitly rated for 60W or 100W, to avoid bottlenecking the wattage.
Step 4: Know it’s safe to use a higher-wattage charger
A 65W charger on a Chromebook rated for 45W won’t overcharge or damage it. The device only draws what it needs; extra available wattage is simply unused headroom.
Step 5: Expect slower charging from lower-wattage chargers
An 18W or 20W phone charger will typically still charge a Chromebook, just noticeably slower, and it may show “plugged in, not charging” if the device is actively in use and drawing more than the charger supplies.
Step 6: Avoid uncertified third-party chargers
Cheap chargers that skip USB-PD certification can deliver incorrect voltage. Stick to reputable brands or the original manufacturer’s charger to protect the charging circuitry long-term.
Still Not Fixed?
If you’ve confirmed you’re using a properly rated, certified charger and cable and the Chromebook still won’t charge reliably, the issue is likely the port or battery rather than the charger. See our full charging diagnostic guide.
FAQ
Can I use my phone charger on my Chromebook?
Yes, as long as it’s USB-C and supports USB-PD, though it will likely charge more slowly than the Chromebook’s rated charger due to lower wattage.
Can I use my Chromebook charger on my phone?
Generally yes, since most phones accept higher wattage than they need and will just charge at their own maximum supported rate.
Does a higher-wattage charger charge my Chromebook faster than its rated speed?
No. The Chromebook only draws up to its own maximum supported charging rate regardless of how much wattage the charger can output.
