Fast only to about eighty percent, then deliberately slow, because the last stretch is where cells are stressed. Heat, not the charger, is what shortens a battery's life.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
filling a glass fast, then slowing at the brim.
For example
The phone races to eighty in half an hour, then crawls the last bit. It is not stuck — it slows down on purpose to be kind to itself.
This is one card out of 275.
The hundred words you meet most are free — the whole set, animated, in one file that works with no internet.
Volume 1 has all 275 in fifteen chapters, with Staying Safe the largest chapter on purpose.