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)