topic Re: Why does the FS26 display the error message "WUEVENT = BATTERY FAIL" after booting? in Power Management

Why does the FS26 display the error message "WUEVENT = BATTERY FAIL" after booting?

Allen_863 — Thu, 11 Dec 2025 08:58:09 GMT

I am using the S32K3X4EVB-T172 for development.

I noticed that after booting up, if I try to read WUEVENT, a BATTERY FAIL error message appears.

This appears to be related to VSUPOV_I, VSUPUV6_I, and VSUPUVH_I, but no errors occurred with these error flags.

Then I used an ADC to read the VSUP voltage, which was approximately 11.925V, while my input voltage was 12V.

How can I prevent the "BATTERY FAIL" message from WUEVENT?

Re: Why does the FS26 display the error message "WUEVENT = BATTERY FAIL" after booting?

TomasVaverka — Fri, 12 Dec 2025 03:22:59 GMT

Hello Allen,

BATTERY FAIL is reported every time POR or VSUP loss. Please write WU_CLR bit to clear wakeup source after device powerup. Those bits are always there if not cleared after device wakeup.

BRs, Tomas

Re: Why does the FS26 display the error message "WUEVENT = BATTERY FAIL" after booting?

Allen_863 — Fri, 12 Dec 2025 03:35:40 GMT

In my code, I wrote IF WUEVENT == 15 / BATTERY FAIL, which is then written to WU_CLR to clear the error. This is because if I execute WU_CLR every time I boot up, I won't see other wake-up notifications like GPIO1_I, GPIO2_I, etc.

However, I'm unsure if this is the correct usage.