diff --git a/libraries/AP_BattMonitor/AP_BattMonitor.cpp b/libraries/AP_BattMonitor/AP_BattMonitor.cpp
index f1d7710bc6..45f630ce3b 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor.cpp
+++ b/libraries/AP_BattMonitor/AP_BattMonitor.cpp
@@ -841,24 +841,25 @@ void AP_BattMonitor::check_failsafes(void)
 // return true if any battery is pushing too much power
 bool AP_BattMonitor::overpower_detected() const
 {
-    bool result = false;
+#if AP_BATTERY_WATT_MAX_ENABLED && APM_BUILD_TYPE(APM_BUILD_ArduPlane)
     for (uint8_t instance = 0; instance < _num_instances; instance++) {
-        result |= overpower_detected(instance);
+        if (overpower_detected(instance)) {
+            return true;
+        }
     }
-    return result;
+#endif
+    return false;
 }
 
 bool AP_BattMonitor::overpower_detected(uint8_t instance) const
 {
-#if APM_BUILD_TYPE(APM_BUILD_ArduPlane)
+#if AP_BATTERY_WATT_MAX_ENABLED && APM_BUILD_TYPE(APM_BUILD_ArduPlane)
     if (instance < _num_instances && _params[instance]._watt_max > 0) {
-        float power = state[instance].current_amps * state[instance].voltage;
+        const float power = state[instance].current_amps * state[instance].voltage;
         return state[instance].healthy && (power > _params[instance]._watt_max);
     }
-    return false;
-#else
-    return false;
 #endif
+    return false;
 }
 
 bool AP_BattMonitor::has_cell_voltages(const uint8_t instance) const
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_Params.cpp b/libraries/AP_BattMonitor/AP_BattMonitor_Params.cpp
index 12ca57ceed..5302bf7730 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_Params.cpp
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_Params.cpp
@@ -40,7 +40,7 @@ const AP_Param::GroupInfo AP_BattMonitor_Params::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("CAPACITY", 7, AP_BattMonitor_Params, _pack_capacity, AP_BATT_MONITOR_BATTERY_CAPACITY),
 
-#ifndef HAL_BUILD_AP_PERIPH
+#if AP_BATTERY_WATT_MAX_ENABLED
     // @Param{Plane}: WATT_MAX
     // @DisplayName: Maximum allowed power (Watts)
     // @Description: If battery wattage (voltage * current) exceeds this value then the system will reduce max throttle (THR_MAX, TKOFF_THR_MAX and THR_MIN for reverse thrust) to satisfy this limit. This helps limit high current to low C rated batteries regardless of battery voltage. The max throttle will slowly grow back to THR_MAX (or TKOFF_THR_MAX ) and THR_MIN if demanding the current max and under the watt max. Use 0 to disable.
@@ -48,7 +48,7 @@ const AP_Param::GroupInfo AP_BattMonitor_Params::var_info[] = {
     // @Increment: 1
     // @User: Advanced
     AP_GROUPINFO_FRAME("WATT_MAX", 8, AP_BattMonitor_Params, _watt_max, 0, AP_PARAM_FRAME_PLANE),
-#endif // HAL_BUILD_AP_PERIPH
+#endif
 
     // @Param: SERIAL_NUM
     // @DisplayName: Battery serial number
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_Params.h b/libraries/AP_BattMonitor/AP_BattMonitor_Params.h
index fff2719f8f..2088845c39 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_Params.h
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_Params.h
@@ -39,7 +39,9 @@ public:
     AP_Int32 _arming_minimum_capacity;  /// capacity level required to arm
     AP_Float _arming_minimum_voltage;   /// voltage level required to arm
     AP_Int32 _options;                  /// Options
+#if AP_BATTERY_WATT_MAX_ENABLED
     AP_Int16 _watt_max;                 /// max battery power allowed. Reduce max throttle to reduce current to satisfy t    his limit
+#endif
     AP_Int8  _type;                     /// 0=disabled, 3=voltage only, 4=voltage and current
     AP_Int8  _low_voltage_timeout;      /// timeout in seconds before a low voltage event will be triggered
     AP_Int8  _failsafe_voltage_source;  /// voltage type used for detection of low voltage event
diff --git a/libraries/AP_BattMonitor/AP_BattMonitor_config.h b/libraries/AP_BattMonitor/AP_BattMonitor_config.h
index 4fab7ff189..92d5ad074e 100644
--- a/libraries/AP_BattMonitor/AP_BattMonitor_config.h
+++ b/libraries/AP_BattMonitor/AP_BattMonitor_config.h
@@ -34,6 +34,10 @@
 #define AP_BATTERY_ESC_TELEM_OUTBOUND_ENABLED 0
 #endif
 
+#ifndef AP_BATTERY_WATT_MAX_ENABLED
+#define AP_BATTERY_WATT_MAX_ENABLED AP_BATTERY_ENABLED
+#endif
+
 #ifndef AP_BATTERY_SMBUS_ENABLED
 #define AP_BATTERY_SMBUS_ENABLED AP_BATTERY_BACKEND_DEFAULT_ENABLED
 #endif