Shimano SM-BTR1 Service Instructions

Hello! I'm a chat assistant, I have read the user manual document for the Shimano SM-BTR1 battery. This document provides safety instructions, usage guidelines, and specifications. It also contains important warnings about potential hazards and proper maintenance. I am ready to assist with any questions you may have about this device.
What should I do if the battery is difficult to insert or remove?

What is the charging time for the battery?

What should I do if battery fluid gets into my eyes?