the idea is to connect a cell, but pins do not seem explicitly available from the boxed [unscrewed] devkit board.
How to wire a cell to it?
Hi, is dev kit or custom board that you mentioned? If dev kit, L53 pin is routed to a super cap, C512.
I am investigating the dev kit option.
specifically looking how to attach a cell to it.
The super cap C512
It should be near J510 and J511, probably somewhere. How to visually recognize it at the dev kit? is it the jack connector?
Found it’s image at the thread: https://devtalk.nvidia.com/default/topic/1043455/jetson-xavier-system-date-and-time-resets-to-jan-28-after-each-reboot-/
It seems to have a battery already
Yes as you attached image, there is a battery (super cap) C512 in there.
may be you as well know where to terminate GPS wires , specifically just two of them, RX and TX?
With a purpose to approach NTP GPS synchronization?
The question has been dedicated into : a separate thread
Redirect to topic: https://devtalk.nvidia.com/default/topic/1051338
how long should the power of the supercap last after shutdown and remove power from the Xavier?
I removed the power at Friday, 25th and today (Monday, 28th) the Xavier shows me with the date command following output: Fr Okt 25 13:30:10 CET 2019
So I think the supercap had enough power to hold time and date, but without ethernet connection time will not be updated. Is this correct? Or in other words, the RTC of Jetson Xavier is not running without main power.
How can I get the correct date and time without ethernet connection?
The RTC on dev kit can only run for couple of hours, if you want to keep time for several days, a big cap or battery is necessary.
Which steps are necessary to add a big cap or battery? At which pins a battery can be connected?
The battery should be attached on pin L53 (VCC_RTC), for details you can refer to OEM DG and ref schematic in DLC.