Please consider RTC Module - Super Capacitor as alternative product This is a Mini Real-Time Clock module, it design for Raspberry Pi, but it also can be used to Arduino. Pluging it into Raspberry Pi GPIO interface, and all is ok. This is the easiest way to keep it in time. Features: Smaller Work in 3.3V and 5V Supported Raspberry Pi and Arduino Compatible with Raspberry Pi A+,B,B+/2. Specification: DS3231 RTC IC Self-adjust 3.3V and 5V Size: 14x14x12 mm Include: 1x RTC Module 1x Battery Document: Adding a Real Time Clock to Raspberry Pi(via learn.adafruit.com)