According to the name, it is easy to know that the Grove High Precision RTC is a more accurate real-time-clock comparing to Grove RTC with the regular clock chip DS1307. The heart of Grove High Precision RTC is PHILIPS PCF85063TP, which is a CMOS chip that optimized for low power consumption, the typical current can be less than 1.2uA at certain environment. All addresses and data are transferred serially via the two-line bidirectional I2C bus, of which the maximum speed is 400kbit/s. An offset register allows fine-tuning of the clock, and the register address is incremented automatically after each read or written data byte.
The Grove High Precision RTC might one the most precise and low consumption RTC you can get so far, If your application requires high precision timing providing, please dont hesitate to get one.