diff --git a/.github/workflows/build_doc.yml b/.github/workflows/build_doc.yml
index d30e1cf31..6575510c5 100644
--- a/.github/workflows/build_doc.yml
+++ b/.github/workflows/build_doc.yml
@@ -15,11 +15,16 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     # Standard drop-in approach that should work for most people.
-
+    - name: Free Disk Space (Ubuntu)
+      uses: insightsengineering/disk-space-reclaimer@v1
+      with:
+        android: true
+        dotnet: true
     - name: Set up Python 3.10
       uses: actions/setup-python@v5
       with:
         python-version: "3.10"
+        cache: 'pip'
 
     - name: Get Python running
       run: |
diff --git a/.github/workflows/build_tests.yml b/.github/workflows/build_tests.yml
index 35a26fc6b..28f5edbb3 100644
--- a/.github/workflows/build_tests.yml
+++ b/.github/workflows/build_tests.yml
@@ -64,11 +64,17 @@ jobs:
         python-version: ["3.10", "3.11", "3.12", "3.13"]
 
     steps:
+    - name: Free Disk Space (Ubuntu)
+      uses: insightsengineering/disk-space-reclaimer@v1
+      with:
+        android: true
+        dotnet: true
     - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
+        cache: 'pip'
     - name: Install POT
       run: |
         pip install -e .
@@ -93,6 +99,7 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: "3.13"
+        cache: 'pip'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip setuptools
@@ -121,6 +128,7 @@ jobs:
        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.python-version }}
+         cache: 'pip'
      - name: Install POT
        run: |
          pip install -e .
@@ -148,6 +156,7 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
+        cache: 'pip'
     - name: RC.exe
       run: |
         function Invoke-VSDevEnvironment {
diff --git a/RELEASES.md b/RELEASES.md
index 4d73da648..ad75950eb 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -11,6 +11,7 @@ This new release adds support for sparse cost matrices in the exact EMD solver.
 - Add support for sparse cost matrices in EMD solver (PR #778, Issue #397)
 - Fix deprecated JAX function in `ot.backend.JaxBackend` (PR #771, Issue #770)
 - Add test for build from source (PR #772, Issue #764)
+- Fix device for batch Ot solver in `ot.batch` (PR #784, Issue #783)
 
 ## 0.9.6.post1
 
diff --git a/ot/batch/_linear.py b/ot/batch/_linear.py
index d6ac6cea4..a63fcb404 100644
--- a/ot/batch/_linear.py
+++ b/ot/batch/_linear.py
@@ -310,9 +310,9 @@ def solve_batch(
     B, n, m = M.shape
 
     if a is None:
-        a = nx.ones((B, n)) / n
+        a = nx.ones((B, n), type_as=M) / n
     if b is None:
-        b = nx.ones((B, m)) / m
+        b = nx.ones((B, m), type_as=M) / m
 
     if solver == "log_sinkhorn":
         K = -M / reg