Maybe I just had bad luck with this module. Does it work only as long as the 5V voltage at VCC. If this voltage is no longer present, then the button cell CR2032 should provide the DS1307 further. Unfortunately, this is not the case, although the pin V-Bat of the DS1307, the required voltage is applied. The date and time are then reset again. Thus this module is only very limited use, but I believe that this is an isolated case, too bad. Two stars I have forgiven only because I got the amount of Neuftech refunded promptly and Neuftech for inquiries provides a really good service.
