Guides
Original explainers on how battery charging actually works, written to back up the numbers our calculator shows.
Why lithium batteries slow down after 80%
The last 20% of a charge often takes as long as the first 80%. Here's the electrochemistry behind the taper, and why it protects your battery.
Fast charging explained: watts, volts and what actually matters
Charger wattage numbers are everywhere, but watts alone don't tell the whole story. How voltage, current limits and your device's own charge controller decide the real speed.