diff --git a/src/platform/nrf52/main-nrf52.cpp b/src/platform/nrf52/main-nrf52.cpp
index 9b26721c0..4bb778ca6 100644
--- a/src/platform/nrf52/main-nrf52.cpp
+++ b/src/platform/nrf52/main-nrf52.cpp
@@ -78,11 +78,18 @@ bool powerHAL_isVBUSConnected()
 
 bool powerHAL_isPowerLevelSafe()
 {
+    static bool powerLevelSafe = true;
 
-    static bool powerLevelSafe = true;  
-
-    uint16_t threshold = SAFE_VDD_VOLTAGE_THRESHOLD * 1000; // convert V to mV
-    uint16_t hysteresis = SAFE_VDD_VOLTAGE_THRESHOLD_HYST * 1000;
+#ifdef SAFE_VDD_VOLTAGE_THRESHOLD_MV
+    uint16_t threshold = SAFE_VDD_VOLTAGE_THRESHOLD_MV;
+#else
+    uint16_t threshold = (uint16_t)(SAFE_VDD_VOLTAGE_THRESHOLD * 1000.0f + 0.5f); // convert V to mV
+#endif
+#ifdef SAFE_VDD_VOLTAGE_THRESHOLD_HYST_MV
+    uint16_t hysteresis = SAFE_VDD_VOLTAGE_THRESHOLD_HYST_MV;
+#else
+    uint16_t hysteresis = (uint16_t)(SAFE_VDD_VOLTAGE_THRESHOLD_HYST * 1000.0f + 0.5f);
+#endif
 
     if (powerLevelSafe) {
         if (getVDDVoltage() < threshold) {
diff --git a/variants/nrf52840/rak_wismeshtag/variant.cpp b/variants/nrf52840/rak_wismeshtag/variant.cpp
index c2a899ed5..1c53bbc0d 100644
--- a/variants/nrf52840/rak_wismeshtag/variant.cpp
+++ b/variants/nrf52840/rak_wismeshtag/variant.cpp
@@ -51,15 +51,31 @@ void variant_nrf52LoopHook(void)
     // If VDD stays unsafe for a while (brownout), force System OFF.
     // Skip when VBUS present to allow recovery while USB-powered.
     if (!powerHAL_isVBUSConnected()) {
+        // Rate-limit VDD safety checks: powerHAL_isPowerLevelSafe() calls getVDDVoltage() each time.
+        static constexpr uint32_t POWER_LEVEL_CHECK_INTERVAL_MS = 100;
+        static uint32_t last_vdd_check_ms = 0;
+        static bool last_power_level_safe = true;
+
+        const uint32_t now = millis();
+        if (last_vdd_check_ms == 0 || (uint32_t)(now - last_vdd_check_ms) >= POWER_LEVEL_CHECK_INTERVAL_MS) {
+            last_vdd_check_ms = now;
+            last_power_level_safe = powerHAL_isPowerLevelSafe();
+        }
+
+        // Do not use millis()==0 as a sentinel: at boot, millis() may be 0 while VDD is unsafe.
+        static bool low_vdd_timer_armed = false;
         static uint32_t low_vdd_since_ms = 0;
-        if (!powerHAL_isPowerLevelSafe()) {
-            if (low_vdd_since_ms == 0)
-                low_vdd_since_ms = millis();
-            if ((uint32_t)(millis() - low_vdd_since_ms) >= (uint32_t)LOW_VDD_SYSTEMOFF_DELAY_MS) {
+
+        if (!last_power_level_safe) {
+            if (!low_vdd_timer_armed) {
+                low_vdd_since_ms = now;
+                low_vdd_timer_armed = true;
+            }
+            if ((uint32_t)(now - low_vdd_since_ms) >= (uint32_t)LOW_VDD_SYSTEMOFF_DELAY_MS) {
                 cpuDeepSleep(portMAX_DELAY);
             }
         } else {
-            low_vdd_since_ms = 0;
+            low_vdd_timer_armed = false;
         }
     }
 }
diff --git a/variants/nrf52840/rak_wismeshtag/variant.h b/variants/nrf52840/rak_wismeshtag/variant.h
index 6014af871..284bba062 100644
--- a/variants/nrf52840/rak_wismeshtag/variant.h
+++ b/variants/nrf52840/rak_wismeshtag/variant.h
@@ -231,8 +231,10 @@ SO GPIO 39/TXEN MAY NOT BE DEFINED FOR SUCCESSFUL OPERATION OF THE SX1262 - TG
 // BAT_ADC divider: R22=1M (top), R24=1.5M (bottom) => V_BAT_ADC = VBAT * (1.5 / (1.0 + 1.5)) = 0.6 * VBAT
 // RAK4630 module: AIN0 = nrf52840 AIN3 = Pin 5 (A0/BATTERY_PIN)
 #define BATTERY_LPCOMP_INPUT NRF_LPCOMP_INPUT_3
-// If VDD is regulated ~3.3V, this wakes around VBAT ~3.09V (good for brownout recovery).
-#define BATTERY_LPCOMP_THRESHOLD NRF_LPCOMP_REF_SUPPLY_9_16  //3.09V NRF_LPCOMP_REF_SUPPLY_9_16 = 3.09V
+// LPCOMP compares the selected input to a fraction of VDD (here 9/16 of VDD at the LPCOMP input).
+// With VDD ≈ 3.3 V: threshold at input ≈ (9/16) * 3.3 V ≈ 1.86 V.
+// BAT_ADC divider: V_BAT_ADC = 0.6 * VBAT → equivalent VBAT ≈ 1.86 / 0.6 ≈ 3.1 V (wake when battery recovers).
+#define BATTERY_LPCOMP_THRESHOLD NRF_LPCOMP_REF_SUPPLY_9_16
 
 // Low voltage protection:
 // If VDD is below SAFE_VDD_VOLTAGE_THRESHOLD for longer than this delay (and no USB VBUS),
@@ -241,12 +243,18 @@ SO GPIO 39/TXEN MAY NOT BE DEFINED FOR SUCCESSFUL OPERATION OF THE SX1262 - TG
 #define LOW_VDD_SYSTEMOFF_DELAY_MS 5000
 #endif
 
+// Prefer integer mV so platform code avoids float→int truncation quirks (e.g. 0.1 V → 99 vs 100 mV).
+#ifndef SAFE_VDD_VOLTAGE_THRESHOLD_MV
+#define SAFE_VDD_VOLTAGE_THRESHOLD_MV 2900
+#endif
+#ifndef SAFE_VDD_VOLTAGE_THRESHOLD_HYST_MV
+#define SAFE_VDD_VOLTAGE_THRESHOLD_HYST_MV 100
+#endif
 #ifndef SAFE_VDD_VOLTAGE_THRESHOLD
-#define SAFE_VDD_VOLTAGE_THRESHOLD 2.9
+#define SAFE_VDD_VOLTAGE_THRESHOLD (SAFE_VDD_VOLTAGE_THRESHOLD_MV / 1000.0f)
 #endif
-
 #ifndef SAFE_VDD_VOLTAGE_THRESHOLD_HYST
-#define SAFE_VDD_VOLTAGE_THRESHOLD_HYST 0.1
+#define SAFE_VDD_VOLTAGE_THRESHOLD_HYST (SAFE_VDD_VOLTAGE_THRESHOLD_HYST_MV / 1000.0f)
 #endif
 
 #define RAK_4631 1