My laptop charges with USB C, so when the standard charger broke, I just used the USB out port from an EcoFlow battery. The display on the battery said the laptop pulled 25-30 watts while charging. So, why can’t I use just any USB brick that can output more than 30 watts?
Is there something that is bound to go wrong that I don’t know about?
Are laptop chargers really that special?
(Edited for clarity)
Volts and amps are negotiated by the USB protocol. All they have to worry about is whether the source can output at least the wattage the laptop requires.