Recommended · for some experience
EEVblog #176 - Lithium Ion/Polymer Battery Charging Tutorial
Why people recommend it
Dave Jones explains how lithium-ion and lithium-polymer cells are charged, including the constant-current and constant-voltage stages, for people building or choosing a charger.
Watch for: runs to about 40 minutes
In their words
This one probably shows the best constant-current and constant-voltage curves: EEVblog #176 - Lithium Ion/Polymer Battery Charging Tutorial
MicroservicesOnDDD on electronics.stackexchange.com, Jan 2019. CC BY-SA.
The charging curve for Li-Ion batteries (explained here) has a final constant voltage stage where the charge voltage plateaus and the charge controller slowly shuts off the current until it reaches some threshold (10% in the video's example) and charger considers the battery full.
graham on electronics.stackexchange.com, Dec 2014. CC BY-SA.
When you have ~40 minutes available, take a look at this video.
AndrejaKo on electronics.stackexchange.com, Jan 2012. CC BY-SA.
