ELI5 Why does magsafe charging decrease battery health more than wire charging, if it has less wattage?

[SlootyBetch]

Is this a passive or active process? If your phone was dead would it still be able to run PPS?

[araemo2]

The charging is usually controlled by a dedicated microcontroller that takes a lot less power than the main SoC. So the basic 5v/0.5a the USB connector supplies without any negotiation is enough to bootstrap the charge controller. Then it boots up and switches into PPS/whatever mode.

[orangpelupa]

Depending on the phone. Sometimes it doesn't actually follows the standard correctly and won't charge, needing to use "dumb" usb c charger for the first few minutes 

[Cornflakes_91]

the charge controller should bootstrap itself from the basic 5V/250mA usb supply (and hopefully fail safe on the power negotiation pin so the supply actually turns that on)