feat(core): fuel gauge parameter tweaks.
What the developer wrote
Authored by kopecdav
feat(core): fuel gauge parameter tweaks.
[no changelog]
What changed, and why it matters
This commit adjusts internal tuning numbers for the battery fuel gauge in Trezor hardware wallets. It changes how the device estimates remaining battery charge, making the estimate smoother and less reactive. There is no indication this affects security, private keys, user data, or device integrity.
No security action required. Treat as normal firmware maintenance / calibration improvement.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The patch modifies Kalman filter covariance parameters (R, Q, R_AGGRESSIVE, Q_AGGRESSIVE) in the STM32U5 power manager. These constants control the trade-off between measurement noise filtering and responsiveness in the battery state-of-charge estimator. The changes are purely algorithmic tuning: R values increase (more trust in the model / less in raw measurements), Q values decrease (slower state updates). No code logic, interfaces, or security boundaries are altered.
Changed components
core/embed/sys/power_manager/stm32u5/power_manager_internal.hInspect captured patch +4 / −4
diff --git a/core/embed/sys/power_manager/stm32u5/power_manager_internal.h b/core/embed/sys/power_manager/stm32u5/power_manager_internal.h
index 174437759..8a27e0bd9 100644
--- a/core/embed/sys/power_manager/stm32u5/power_manager_internal.h
+++ b/core/embed/sys/power_manager/stm32u5/power_manager_internal.h
@@ -42,10 +42,10 @@
#define PM_SELF_DISG_RATE_SUSPEND_MA 0.032f
// Fuel gauge extended kalman filter parameters
-#define PM_FUEL_GAUGE_R 2000.0f
-#define PM_FUEL_GAUGE_Q 0.0003f
-#define PM_FUEL_GAUGE_R_AGGRESSIVE 1500.0f
-#define PM_FUEL_GAUGE_Q_AGGRESSIVE 0.0004f
+#define PM_FUEL_GAUGE_R 3500.0f
+#define PM_FUEL_GAUGE_Q 0.0001f
+#define PM_FUEL_GAUGE_R_AGGRESSIVE 3000.0f
+#define PM_FUEL_GAUGE_Q_AGGRESSIVE 0.0002f
#define PM_FUEL_GAUGE_P_INIT 0.1f
// Timeout after which the device automatically transit from suspend to
Why this scored 15/100
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