Originally posted by totsmuyco I just recently received my K-3II and thought that it has the same battery as my k-5II. I found that the K-3Ii has the D-Li90P and my k-5II uses D-Li90. The D-Li90P has 4 terminals while D-Li90 has 3. Some said that you can use K-5 batteries on the K-3 and vice versa. Wouldn't that be harmful? I hope you fuus can help. Thanks.
The additional pin is used only by the charger. See this thread:
https://www.pentaxforums.com/forums/16-pentax-news-rumors/190153-new-battery-...90p-why-3.html