I think everyone is talking about the ZS-042
https://forum.arduino.cc/index.php?topic=278270.0
The charging circuit should be cut, unless the module is operated on 3.3V. To use it to generate alarms with a processor in low power mode, you also need to get rid of the pullup resistors in RP1 that are connected to SQW and 32KHZ, you can cut traces or remove the pack. If you remove the pack, it removes the I2C pull ups as well so you need to take account of that. I'm not sure how much power is used by the on board EEPROM, but consider that as well.
The sad thing is, there are several good DS3231 modules on the market that don't have need of these modifications, but everyone keeps gravitating back to this one (and talking about it as if the chip and module are one and the same).