battery: only propagate warning state in upwards

src/modules/systemlib/battery.cpp

@@ -225,14 +225,14 @@ void
 Battery::determineWarning(bool connected)
 {
 	if (connected) {
-		// Smallest values must come first
-		if (_remaining < _param_emergency_thr.get()) {
+		// propagate warning state only if the state is higher, otherwise remain in current waringin state
+		if (_remaining < _param_emergency_thr.get() || (_warning == battery_status_s::BATTERY_WARNING_EMERGENCY)) {
 			_warning = battery_status_s::BATTERY_WARNING_EMERGENCY;
 
-		} else if (_remaining < _param_crit_thr.get()) {
+		} else if (_remaining < _param_crit_thr.get() || (_warning == battery_status_s::BATTERY_WARNING_CRITICAL)) {
 			_warning = battery_status_s::BATTERY_WARNING_CRITICAL;
 
-		} else if (_remaining < _param_low_thr.get()) {
+		} else if (_remaining < _param_low_thr.get() || (_warning == battery_status_s::BATTERY_WARNING_LOW)) {
 			_warning = battery_status_s::BATTERY_WARNING_LOW;
 		}
 	}