Originally Posted by felonwan
I found that the battery have 4 electrodes. I don't know the function of the two with signs of c and d. It is properly the circuits of security.
Is that possible to cheat the Kindle by using a different battery or a AC adapter?
Incorrect charging can destroy your battery, and possibly start a fire. The extra battery terminals are used by lithium battery chargers, and to communicate with the kindle (which can read the battery internal serial number and other information).
EDIT: The kindle firmware interrogates the battery to verify that it is an AUTHENTIC amazon-approved battery. However, battery manufacturers can (and do) create clones that will pass the authenticity check, even if they do not contain all required safety features. Cheap replacement batteries may not be as safe a REAL authentic approved batteries.