diff --git a/notebook_nueva/battery_holder.py b/notebook_nueva/battery_holder.py
index c305e2c..c6c14b5 100644
--- a/notebook_nueva/battery_holder.py
+++ b/notebook_nueva/battery_holder.py
@@ -1,4 +1,5 @@
 import cadquery as cq
+from utils import punch_hole2, extrude_shape, punch_hole
 
 stand_positions = [(3.5, 3.5), (61.5, 3.5), (61.5, 52.5), (3.5, 52.5)]
 stands = (
@@ -72,7 +73,7 @@ elements = [
 hex_size = width // 13
 vent_positions = []
 for x in range(1, width // hex_size):
-    for y in range(0, int(height // hex_size / 0.8) - 1):
+    for y in range(1, int(height // hex_size / 0.8)):
         vent_positions.append(
             (
                 (x + (y % 2) / 2) * hex_size - hex_size * 0.2,
@@ -99,16 +100,67 @@ holes = [
     {
         "x": -15,
         "y": -1 + pillar_height,
-        "height": 6.5,
-        "width": 12,
-        "fillet": 1,
+        "shape": cq.Sketch().trapezoid(12, 6.5, 90, mode="a").vertices().fillet(1),
     },
     # Power button
     {
         "x": -67,
         "y": 5.5 + pillar_height,
-        "height": 7,
-        "width": 7,
-        "fillet": 1,
+        "shape": cq.Sketch().trapezoid(7, 7, 90, mode="a").vertices().fillet(1),
     },
 ]
+
+
+def add(
+    *,
+    model,
+    width,
+    height,
+    thickness,
+    offset_x,
+    offset_y,
+    bottom_face,
+    back_face,
+    shell_t
+):
+
+    # Vents
+    for vent in vents:
+        model = punch_hole2(
+            model=model,
+            face=bottom_face,
+            w=width,
+            h=height,
+            x_offset=offset_x + vent["x"],
+            y_offset=shell_t + offset_y + vent["y"],
+            hole=vent,
+            depth=shell_t,
+        )
+
+    # Battery holder stands and pogo pin holder
+    for element in elements:
+        model = extrude_shape(
+            model=model,
+            face=bottom_face,
+            w=width,
+            h=height,
+            x_offset=offset_x + element["x"],
+            y_offset=shell_t + offset_y + element["y"],
+            shape=element["shape"],
+            height=-(element["height"] + shell_t),
+        )
+
+    # Holes
+    for hole in holes:
+        model = punch_hole2(
+            model=model,
+            face=back_face,
+            w=width,
+            h=thickness,
+            x_offset=width - offset_x,
+            y_offset=shell_t,
+            hole=hole,
+            depth=shell_t,
+        )
+
+    return model
diff --git a/notebook_nueva/left_side.stl b/notebook_nueva/left_side.stl
index 68c8469..7b298c4 100644
Binary files a/notebook_nueva/left_side.stl and b/notebook_nueva/left_side.stl differ
diff --git a/notebook_nueva/model.stl b/notebook_nueva/model.stl
index 3bfd904..bce2073 100644
Binary files a/notebook_nueva/model.stl and b/notebook_nueva/model.stl differ
diff --git a/notebook_nueva/modelo.py b/notebook_nueva/modelo.py
index 6302030..dbe37e5 100644
--- a/notebook_nueva/modelo.py
+++ b/notebook_nueva/modelo.py
@@ -153,19 +153,6 @@ def model():
     # Now the basic box shape is in place, start adding things
     # and cutting holes.
 
-    # Holes in the back of the case for battery holder
-    for hole in battery_holder.holes:
-        model = punch_hole(
-            model=model,
-            face=">Y",
-            w=width,
-            h=thickness,
-            x_offset=width - battery_offset_x,
-            y_offset=shell_t,
-            hole=hole,
-            depth=shell_t,
-        )
-
     # Hole for USB hub in the back
     for hole in usb_hub.holes:
         model = punch_hole(
@@ -205,31 +192,6 @@ def model():
             depth=shell_t,
         )
 
-    for vent in battery_holder.vents:
-        model = punch_hole2(
-            model=model,
-            face="<Z",
-            w=width,
-            h=height,
-            x_offset=battery_offset_x + element["x"],
-            y_offset=shell_t + battery_offset_y + element["y"],
-            hole=vent,
-            depth=shell_t,
-        )
-
-    # Battery holder stands and pogo pin holder
-    for element in battery_holder.elements:
-        model = extrude_shape(
-            model=model,
-            face="<Z",
-            w=width,
-            h=height,
-            x_offset=battery_offset_x + element["x"],
-            y_offset=shell_t + battery_offset_y + element["y"],
-            shape=element["shape"],
-            height=-(element["height"] + shell_t),
-        )
-
     # CPU holder stands
     for element in cpu_holder.elements:
         model = extrude_shape(
@@ -243,6 +205,19 @@ def model():
             height=-(element["height"] + shell_t),
         )
 
+    # This adds all the holes and extrusions for the battery system
+    model = battery_holder.add(
+        model=model,
+        width=width,
+        height=height,
+        thickness=thickness,
+        offset_x=battery_offset_x,
+        offset_y=battery_offset_y,
+        bottom_face="<Z",
+        back_face=">Y",
+        shell_t=shell_t,
+    )
+
     return model