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)
As long as it supports the USB-C PowerDelivery standard and has the supported voltages and wattage needed to do so. Most laptops will need 20v.
For chargers as small as those little phone-bricks the main problems would probably be the wiregauge of the USBC cable and the heat. Being so small and without exhaust vents I imagine the poor little charger would be at risk of early heat death. But it’s doable
I’ve been able to normal-charge a 15 inch IdeaPad 82R9 using a little 1x1 inch 35watt GaN charger. But this was with the CPU locked to not go over 25% load(this laptop is FAST even with this sacrifice) and it makes that little charger get pretty hot. Without that CPU limit in place it actually drains faster than the charger can charge.
Modern GAN chargers can handle 65w in a pretty small charger though.