We start to use RTC coin 3V battery connected to BAT_RTC pin to keep time in case the main power supply is disconnected. It works, but inaccuracy is surprising - more then one hour during 8 hours.
I cannot find RTC accuracy specification in WP7602 data sheet. Is it the reason why battery components are not assembled on Redboard?
And one note to R306 value (10k) - average consumption I can measure is 5 uAmps as declared, but there are 30 ms current pulses up to 150uA which can make significant drop on BAT_RTC.
Please help or explain.
I can confirm that described problem with very inaccurate RTC is also similar at WP8548 module. I have not found infulance of FW version.
In addition, I have found that the consumption from a 3V battery reaches values > 150uA periodically for tens of seconds.
I have encountered also serious problem when Module cannot start after re-connection of main power supply and has to be recovered.
So guys, has somebody use 3V RTC battery?