"To charge a laptop" means to connect it to a power source, usually through a charging cable, to replenish its battery and provide it with electrical energy. Full definition
It even gets a handy 240 - volt power socket for charging laptops and the like. (autoexpress.co.uk)
I was able to charge my laptop with it several times on a full charge, and had no issues. (treehugger.com)
You could even charge your laptop from one of those portable battery packs you charge your smartphones and other portable devices from today. (howtogeek.com)