Originally Posted by
SuperG1955
My understanding is that the seat power is not 15A service but that it's limited to 45W, which is only 3A. There were many notebooks a few years ago who's power packs drew 45W but the minimum nowadays seems to be 65W with many notebook computers using 90 and even 135W. When a device is plugged in which draws more power than a circuit is designed for, a circuit breaker trips and prevents the overload.
The max limit per the FAA is 100W, Delta's are rated for 75W but really they will run up to 90W without too much issue. Laptop transformers can handle a little voltage drop at the higher end of the wattage pull without issue.
That said, on the chargers it's the opposite of what you said... virtually no laptop has a 90-135W charger these days unless you're talking about a gaming laptop or an analytics/developer laptop workstation. I can't think of a single business oriented laptop that is above 65W. Laptops are such power sippers nowadays that they never really draw above 30W on their own (typically 5-7 watts when not under super high load, 2-5 watts when idle almost all going to power the screen), and their batteries are typically 40-60Wh. So 65W is enough to both power the laptop under load and charge the battery from empty in 90 minutes or less (assuming no trickle charging at the top end which there would be).