diff --git a/test/test_encode.py b/test/test_encode.py
index 12afdc07..b579657e 100644
--- a/test/test_encode.py
+++ b/test/test_encode.py
@@ -174,7 +174,7 @@ def test_loss_falls(self):
         vae = vamb.encode.VAE(self.rpkm.shape[1])
         rpkm_copy = self.rpkm.copy()
         tnfs_copy = self.tnfs.copy()
-        dl, mask = vamb.encode.make_dataloader(
+        dl, _ = vamb.encode.make_dataloader(
             rpkm_copy, tnfs_copy, self.lens, batchsize=16, destroy=True
         )
         di = torch.Tensor(rpkm_copy)
@@ -202,10 +202,20 @@ def test_loss_falls(self):
         after_encoding = vae_2.encode(dl)
         self.assertTrue(np.all(np.abs(before_encoding - after_encoding) < 1e-6))
 
+    def test_warn_too_many_batch_steps(self):
+        vae = vamb.encode.VAE(self.rpkm.shape[1])
+        rpkm_copy = self.rpkm.copy()
+        tnfs_copy = self.tnfs.copy()
+        dl, _ = vamb.encode.make_dataloader(
+            rpkm_copy, tnfs_copy, self.lens, batchsize=16, destroy=True
+        )
+        with self.assertWarns(Warning):
+            vae.trainmodel(dl, nepochs=4, batchsteps=[1, 2, 3])
+
     def test_encoding(self):
         nlatent = 15
         vae = vamb.encode.VAE(self.rpkm.shape[1], nlatent=nlatent)
-        dl, mask = vamb.encode.make_dataloader(
+        dl, _ = vamb.encode.make_dataloader(
             self.rpkm, self.tnfs, self.lens, batchsize=32
         )
         encoding = vae.encode(dl)
diff --git a/vamb/encode.py b/vamb/encode.py
index 5e380b34..221a34cd 100644
--- a/vamb/encode.py
+++ b/vamb/encode.py
@@ -9,6 +9,7 @@
 from torch import nn as _nn
 from math import log as _log
 from time import time
+import warnings
 
 __doc__ = """Encode a depths matrix and a tnf matrix to latent representation.
 
@@ -379,7 +380,7 @@ def trainepoch(
         epoch_celoss = 0.0
 
         if epoch in batchsteps:
-            data_loader = set_batchsize(data_loader, data_loader.batch_size * 2)
+            data_loader = set_batchsize(data_loader, data_loader.batch_size * 2)  # type: ignore
 
         for depths_in, tnf_in, weights in data_loader:
             depths_in.requires_grad = True
@@ -450,7 +451,7 @@ def encode(self, data_loader) -> _np.ndarray:
 
         row = 0
         with _torch.no_grad():
-            for depths, tnf, weights in new_data_loader:
+            for depths, tnf, _ in new_data_loader:
                 # Move input to GPU if requested
                 if self.usecuda:
                     depths = depths.cuda()
@@ -551,28 +552,41 @@ def trainmodel(
         if nepochs < 1:
             raise ValueError("Minimum 1 epoch, not {nepochs}")
 
-        if batchsteps is None:
-            batchsteps_set: set[int] = set()
+        if batchsteps is None or len(batchsteps) == 0:
+            sorted_batch_steps: list[int] = []
         else:
             # First collect to list in order to allow all element types, then check that
             # they are integers
-            batchsteps = list(batchsteps)
             if not all(isinstance(i, int) for i in batchsteps):
                 raise ValueError("All elements of batchsteps must be integers")
-            if max(batchsteps, default=0) >= nepochs:
+            sorted_batch_steps = sorted(set(batchsteps))
+            if sorted_batch_steps[0] < 1:
+                raise ValueError(
+                    f"Minimum of batchsteps must be 1, not {sorted_batch_steps[0]}"
+                )
+            if sorted_batch_steps[-1] >= nepochs:
                 raise ValueError("Max batchsteps must not equal or exceed nepochs")
-            last_batchsize = dataloader.batch_size * 2 ** len(batchsteps)
-            if len(dataloader.dataset) < last_batchsize:  # type: ignore
+
+            n_contigs = len(dataloader.dataset)  # type: ignore
+            starting_batch_size: int = dataloader.batch_size  # type: ignore
+            if n_contigs < starting_batch_size:
                 raise ValueError(
-                    f"Last batch size of {last_batchsize} exceeds dataset length "
-                    f"of {len(dataloader.dataset)}. "  # type: ignore
+                    f"Starting batch size of {starting_batch_size} exceeds dataset length "
+                    f"of {n_contigs}. "
                     "This means you have too few contigs left after filtering to train. "
                     "It is not adviced to run Vamb with fewer than 10,000 sequences "
                     "after filtering. "
                     "Please check the Vamb log file to see where the sequences were "
                     "filtered away, and verify BAM files has sensible content."
                 )
-            batchsteps_set = set(batchsteps)
+            maximum_batch_steps = (n_contigs // starting_batch_size).bit_length() - 1
+            if maximum_batch_steps < len(sorted_batch_steps):
+                warnings.warn(
+                    f"Requested {len(sorted_batch_steps)} batch steps, but with a starting "
+                    f"batch size of {starting_batch_size} and {n_contigs} contigs, "
+                    f"only the first {maximum_batch_steps} batch steps can be used."
+                )
+                sorted_batch_steps = sorted_batch_steps[:maximum_batch_steps]
 
         # Get number of features
         # Following line is un-inferrable due to typing problems with DataLoader
@@ -591,8 +605,8 @@ def trainmodel(
             print("\tN epochs:", nepochs, file=logfile)
             print("\tStarting batch size:", dataloader.batch_size, file=logfile)
             batchsteps_string = (
-                ", ".join(map(str, sorted(batchsteps_set)))
-                if batchsteps_set
+                ", ".join(map(str, sorted_batch_steps))
+                if len(sorted_batch_steps) > 0
                 else "None"
             )
             print("\tBatchsteps:", batchsteps_string, file=logfile)
@@ -603,7 +617,7 @@ def trainmodel(
         # Train
         for epoch in range(nepochs):
             dataloader = self.trainepoch(
-                dataloader, epoch, optimizer, sorted(batchsteps_set), time(), logfile
+                dataloader, epoch, optimizer, sorted_batch_steps, time(), logfile
             )
 
         # Save weights - Lord forgive me, for I have sinned when catching all exceptions