I just received my Rasclock V4, and set it up according to Afterthought's instructions. Seeing as I'm doing this on a RPi B+, with the latest raspbian image downloaded from raspberrypi.org just yesterday I assumed i could use the instructions for new firmware (just enabling the dtoverlay).
All of this seems to work. the
hwclock command seems to respond normally (no errors, time is set and read correctly).
When I reboot or shut down the RPi however, the time is all wrong when it comes back up. With fake-hwclock still in place, it showed a difference of the reboot-time (or duration of shutdown) and with fake-hwclock removed, it initializes on the UNIX epoch.
I verified the battery is good. It's brand new out of the blister, and reads 3.17V.
Further troubleshooting led me to trying other installation methods, all succesful when powered on, but the same result after reboots or shutdowns. I2C however does work, and the rasclock is detected using i2cdetect.
Is my Rasclock faulty, or did I still do something wrong?