We have a #PCF2129 RTC connected to an mcu via i2c. The i2c is shared by 2 other devices. The system works fine when the battery is not connected. All three slaves works fine over a single i2c. But when we connected the battery to the RTC the entire i2c operation hangs up. The system has a display which shows the current time on #RTC. The system is able to retain the correct value without battery after a software reset.
Is there some configuration change that is needed to be made to make it work with a 3v battery?