How to connect a RTC backup battery

Started by rinni, November 22, 2021, 08:23:59 pm

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I need connect a RTC backup battery to the board (2Ge8G-IND, Rev. E) and I'm kind of lost ... Should it be connected to GPIO1 pin4 (+) and pin2 (-) or how is it supposed to work?



No. Backup battery is on separate pads named "BACKUP". These are two pinholes available near the UART0 (serial debug) pins. Refer to the schematic.

The battery should be 3V. Check on the AXP209 datasheet for the requirements and properties of the backup RTC battery.
Technical support and documentation manager at Olimex


November 28, 2021, 06:08:20 pm #2 Last Edit: November 29, 2021, 10:16:50 pm by rinni
I can't find anything like that in the schematic nor do I see any pinholes (besides the UEXT ones) near the UART0 (three pinholes on the lower right):