Recommended · for some experience
Shorting out a fully charged cheap lithium jump starter. (It didn't end well.)
Why people recommend it
BigClive opens a lithium jump starter power bank, estimating its peak current with improvised methods and showing cable and cell resistance effects in practice.
Watch for: high current lithium cells; the timestamped section covers pack pressure effects
In their words
BigClive on Youtube took such a product apart, see:
Bimpelrekkie on electronics.stackexchange.com, Jan 2018. CC BY-SA.
See BigClive for a practical demonstration (who even uses the voltage drop over a copper pipe as a resistor to estimate the current)
Jens on electronics.stackexchange.com, May 2018. CC BY-SA.
