AB Electronics UK RTC HAT for Raspberry Pi

The RTC HAT for Raspberry Pi is a battery backed real-time clock module for the Raspberry Pi. It keeps track of the time while the Raspberry Pi is switched off and allows the Raspberry Pi to retrieve the current date and time from the RTC Pi when it is switched back on. Battery backed real-time clock module; 56-Byte, General-Purpose RAM with Unlimited Writes; Compatible with Raspberry Pi 3,; Raspberry Pi 2; and Raspberry Pi Model B+; Supply Voltage: 4.5V to 5.5V