Some issues with RTC external battery and device boot

Hi everyone, I met some problems with the RTC external battery and device boot, please let me describe the problem in detail.
I’m using jetson orin nano module(p3767-0003) and my custom board, the RTC external battery connected to the board.
为了更清楚地描述问题,我还是用中文描述好了:
我通过重新编译内核启用了RTC0,搭配我们的定制底板,在常温下是正常启动的,RTC时间保存也是正常的。
但是在高温环境(60摄氏度)下给板卡上电会偶发无法启动的问题,该情况下调试串口无任何输出,电源指示灯也不亮,再次上电就可以正常启动,但RTC时间被复位,无法保存,经过多次尝试发现只有出现上电无法启动的情况下RTC时间被复位,上电正常启动则RTC时间也正常。
拔下RTC外置电池后上述问题则不会出现,请问上述问题和RTC外置电池有何潜在关联,我们该从哪个方向排查该问题

你可以先找一塊DevKit接電池驗證一下嗎

Hi DaveYYY
我们尝试在jetson-orin-nano-devkit上连接了外置RTC电池,刷写的kernel与custom board一致 ,我们确认devkit board中/dev/rtc指向的是/dev/rtc0,但是哪怕是在常温下也无法像custom board一样保存RTC时间。

先量一下接電池之後PMIC_BBAT這根pin有沒有電

Hi DaveYYY
确认是有电的,电压应该也在规定范围内



使我们疑惑的是,硬件工程师确认连接外置电池方式与custom board一致,为什么custom board常温下可以保存RTC时间,而devkit board常温下却无法保存

Hi, please use default kernel to test on devkit.

Please probe the power on/off sequence first, so as to make sure carrier rails are turned on after module rails during power on and turned off earlier during power off.