diff --git a/README.md b/README.md
index 682f92af..90b5a14f 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 ![KiBot Logo](https://raw.githubusercontent.com/INTI-CMNB/KiBot/master/docs/images/kibot_740x400_logo.png)
 
-[![Python application](https://img.shields.io/github/actions/workflow/status/INTI-CMNB/KiBot/pythonapp.yml?branch=dev&style=plastic)](https://github.com/INTI-CMNB/KiBot/actions)
+[![Python application](https://img.shields.io/github/actions/workflow/status/INTI-CMNB/KiBot/pythonapp.yml?branch=subpcb&style=plastic)](https://github.com/INTI-CMNB/KiBot/actions)
 [![Coverage Status](https://img.shields.io/coveralls/github/INTI-CMNB/KiBot?style=plastic)](https://coveralls.io/github/INTI-CMNB/KiBot?branch=master)
 [![PyPI version](https://img.shields.io/pypi/v/kibot?style=plastic)](https://pypi.org/project/kibot/)
 [![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg?style=plastic)](https://www.paypal.com/donate/?hosted_button_id=K2T86GDTTMRPL)
@@ -586,13 +586,14 @@ The pattern uses the following expansions:
 - **%I** an ID defined by the user for this output.
 - **%p** pcb/sch title from pcb metadata.
 - **%r** revision from pcb/sch metadata.
+- **%S** sub-PCB name (related to multiboards).
 - **%T** time the script was started.
 - **%x** a suitable extension for the output type.
 - **%v** the `file_id` of the current variant, or the global variant if outside a variant scope.
 - **%V** the `name` of the current variant, or the global variant if outside a variant scope.
 
 They are compatible with the ones used by IBoM.
-The default value for `global.output` is `%f-%i.%x`.
+The default value for `global.output` is `%f-%i%I%v.%x`.
 If you want to include the revision you could add the following definition:
 
 ```yaml
@@ -5228,3 +5229,4 @@ This case is [discussed here](docs/1_SCH_2_part_PCBs)
   - **Most icons for the navigate_results output**: The KiCad project
   - **PTV09A 3D Model**: Dmitry Levin ([GrabCad](https://grabcad.com/dmitry.levin-6))
   - **PcbDraw PCB example**: [Arduino Learning Kit Starter](https://github.com/RoboticsBrno/ArduinoLearningKitStarter)
+  - **Battery charger example**: [RB0002-BatteryPack](https://cadlab.io/project/22740/master/files)
diff --git a/docs/README.in b/docs/README.in
index 521a7236..438c1dd4 100644
--- a/docs/README.in
+++ b/docs/README.in
@@ -390,13 +390,14 @@ The pattern uses the following expansions:
 - **%I** an ID defined by the user for this output.
 - **%p** pcb/sch title from pcb metadata.
 - **%r** revision from pcb/sch metadata.
+- **%S** sub-PCB name (related to multiboards).
 - **%T** time the script was started.
 - **%x** a suitable extension for the output type.
 - **%v** the `file_id` of the current variant, or the global variant if outside a variant scope.
 - **%V** the `name` of the current variant, or the global variant if outside a variant scope.
 
 They are compatible with the ones used by IBoM.
-The default value for `global.output` is `%f-%i.%x`.
+The default value for `global.output` is `%f-%i%I%v.%x`.
 If you want to include the revision you could add the following definition:
 
 ```yaml
@@ -1960,3 +1961,4 @@ This case is [discussed here](docs/1_SCH_2_part_PCBs)
   - **Most icons for the navigate_results output**: The KiCad project
   - **PTV09A 3D Model**: Dmitry Levin ([GrabCad](https://grabcad.com/dmitry.levin-6))
   - **PcbDraw PCB example**: [Arduino Learning Kit Starter](https://github.com/RoboticsBrno/ArduinoLearningKitStarter)
+  - **Battery charger example**: [RB0002-BatteryPack](https://cadlab.io/project/22740/master/files)
diff --git a/kibot/optionable.py b/kibot/optionable.py
index 62eebb9f..c16ab938 100644
--- a/kibot/optionable.py
+++ b/kibot/optionable.py
@@ -264,6 +264,20 @@ class Optionable(object):
             return self.variant.name
         return Optionable._find_global_variant_name()
 
+    @staticmethod
+    def _find_global_subpcb():
+        if GS.solved_global_variant and GS.solved_global_variant._sub_pcb:
+            return GS.solved_global_variant._sub_pcb.name
+        return ''
+
+    def _find_subpcb(self):
+        """ Returns the name of the sub-PCB.
+            Also try with the globally defined variant.
+            If no variant is defined an empty string is returned. """
+        if hasattr(self, 'variant') and self.variant and self.variant._sub_pcb:
+            return self.variant._sub_pcb.name
+        return Optionable._find_global_variant()
+
     def expand_filename_common(self, name, parent):
         """ Expansions common to the PCB and Schematic """
         # PCB expansions, explicit
@@ -295,6 +309,7 @@ class Optionable(object):
             name = name.replace('%i', self._expand_id)
             name = name.replace('%v', _cl(self._find_variant()))
             name = name.replace('%V', _cl(self._find_variant_name()))
+            name = name.replace('%S', _cl(self._find_subpcb()))
             name = name.replace('%x', self._expand_ext)
             replace_id = ''
             if parent and hasattr(parent, 'output_id'):