Excellent compact SMT design intended for embedded applications, made by Sparkfun.
This tiny assembly contains I2C compatible RTC chip DS1307, clock crystal, back up lithium coin cell (CR1225 41mAh) battery and 5-pin connector.
I2C interface allows easy integration into any microcontroller based design.
Fresh battery should provide enough energy to support time keeping capability for very long time without external 5V power. According to Sparkfun, up to 9 years.
Well, I cannot wait such a long term to prove it so I take it as is;-)
|Real time clock DS1307.|