BUY M48T86MH1 https://www.utsource.net/itm/p/127908.html
5.0 V PC real-time clock
The M48T86MH1 is a low-power CMOS real-time clock (RTC) IC with a built-in crystal oscillator. It is designed to provide time and date information for a wide range of applications.
Features:
Low power consumption
Built-in oscillator
Battery-backed RAM
24-hour alarm
Leap year correction
Automatic power-fail detect
Programmable output
Programmable interrupt
Low voltage detection
Applications:
Automotive
Industrial
Medical
Home appliances
Security systems
Networking equipment
Embedded systems
(For reference only)