How do biki bikes work?

Can you explain in detail how biki bikes operate and function in their intended environment? Are they user-friendly and easy to navigate? How does the rental process work, and are there any specific requirements or steps that riders need to follow before they can start pedaling? Also, how does the system ensure the bikes are maintained and in good working condition for all users? Additionally, is there a limit to how long riders can use the bikes or are there any penalties for not returning them on time?