Update the simpleBattery module documentation with fault message

Update the simpleBattery module documentation with fault message

src/simulation/power/simpleBattery/simpleBattery.rst

@@ -37,7 +37,9 @@ The next step is to attach one or more :ref:`PowerNodeUsageMsgPayload` instances
 
 For more information on how to set up and use this module, see the simple power system example :ref:`scenarioPowerDemo`.
 
-To simulate a battery capacity fault that reduces the actual storage capacity (without directly altering the stated capacity), users must set up the fault flag::
+Users must configure the fault message to simulate a battery capacity fault that reduces the actual storage capacity while the ``storageCapacity`` value remains unchanged. The faulted battery capacity is determined using the ``faultCapacityRatio``, calculated as (actual capacity) / (set capacity). ::
 
-   battery.fault = True
-   battery.faultCapacityRatio = 0.5 # 50% of the original capacity
+   faultMsg = messaging.PowerStorageFaultMsgPayload()
+   faultMsg.faultCapacityRatio = 0.3 # Actual capacity is 30% of the nominal capacity
+   faultStatusMsg = messaging.PowerStorageFaultMsg().write(faultMsg)
+   battery.batteryFaultInMsg.subscribeTo(faultStatusMsg)