diff --git a/src/cnn/backpropagation.c b/src/cnn/backpropagation.c
index ae4134a..f4ba882 100644
--- a/src/cnn/backpropagation.c
+++ b/src/cnn/backpropagation.c
@@ -50,13 +50,13 @@ void backward_2d_pooling(float*** input, float*** output, int input_width, int o
 void backward_fully_connected(Kernel_nn* ker, float* input, float* input_z, float* output, int size_input, int size_output, ptr d_function, int is_first) {
     // Bias
     for (int j=0; j < size_output; j++) {
-        ker->d_bias[j] = output[j];
+        ker->d_bias[j] += output[j];
     }
 
     // Weights
     for (int i=0; i < size_input; i++) {
         for (int j=0; j < size_output; j++) {
-            ker->d_weights[i][j] = input[i]*output[j];
+            ker->d_weights[i][j] += input[i]*output[j];
         }
     }
 
diff --git a/src/cnn/include/train.h b/src/cnn/include/train.h
index 9057f8b..37ca0fe 100644
--- a/src/cnn/include/train.h
+++ b/src/cnn/include/train.h
@@ -5,8 +5,9 @@
 #define DEF_TRAIN_H
 
 #define EPOCHS 10
-#define BATCHES 120
+#define BATCHES 500
 #define USE_MULTITHREADING
+#define LEARNING_RATE 0.01
 
 
 /*
@@ -24,6 +25,7 @@ typedef struct TrainParameters {
     int start; // Début des images
     int nb_images; // Nombre d'images àn traiter
     float accuracy; // Accuracy (à renvoyer)
+    float loss; // Loss (à renvoyer)
 } TrainParameters;
 
 
diff --git a/src/cnn/include/update.h b/src/cnn/include/update.h
index c37881a..4b50be9 100644
--- a/src/cnn/include/update.h
+++ b/src/cnn/include/update.h
@@ -7,13 +7,13 @@
 * Met à jours les poids à partir de données obtenus après plusieurs backpropagations
 * Puis met à 0 tous les d_weights
 */
-void update_weights(Network* network, Network* d_network, int nb_images);
+void update_weights(Network* network, Network* d_network);
 
 /*
 * Met à jours les biais à partir de données obtenus après plusieurs backpropagations
 * Puis met à 0 tous les d_bias
 */
-void update_bias(Network* network, Network* d_network, int nb_images);
+void update_bias(Network* network, Network* d_network);
 
 /*
 * Met à 0 toutes les données de backpropagation de poids
diff --git a/src/cnn/train.c b/src/cnn/train.c
index 9e54086..ccc65c1 100644
--- a/src/cnn/train.c
+++ b/src/cnn/train.c
@@ -40,12 +40,21 @@ void* train_thread(void* parameters) {
     int dataset_type = param->dataset_type;
     int start = param->start;
     int nb_images = param->nb_images;
+
+    float* wanted_output;
     float accuracy = 0.;
+    float loss = 0.;
+
     for (int i=start;  i < start+nb_images; i++) {
         if (dataset_type == 0) {
             write_image_in_network_32(images[index[i]], height, width, network->input[0][0]);
             forward_propagation(network);
             maxi = indice_max(network->input[network->size-1][0][0], 10);
+            
+            wanted_output = generate_wanted_output(labels[index[i]], 10);
+            loss += compute_mean_squared_error(network->input[network->size-1][0][0], wanted_output, 10);
+            free(wanted_output);
+
             backward_propagation(network, labels[index[i]]);
 
             if (maxi == labels[index[i]]) {
@@ -72,6 +81,7 @@ void* train_thread(void* parameters) {
     }
 
     param->accuracy = accuracy;
+    param->loss = loss;
     return NULL;
 }
 
@@ -81,6 +91,9 @@ void train(int dataset_type, char* images_file, char* labels_file, char* data_di
     Network* network;
     int input_dim = -1;
     int input_depth = -1;
+
+    float loss;
+    float batch_loss; // May be redundant with loss, but gives more informations
     float accuracy;
     float current_accuracy;
 
@@ -121,9 +134,10 @@ void train(int dataset_type, char* images_file, char* labels_file, char* data_di
 
     // Initialisation du réseau
     if (!recover) {
-        network = create_network_lenet5(0.1, 0, TANH, GLOROT, input_dim, input_depth);
+        network = create_network_lenet5(LEARNING_RATE, 0, TANH, GLOROT, input_dim, input_depth);
     } else {
         network = read_network(recover);
+        network->learning_rate = LEARNING_RATE;
     }
 
 
@@ -201,13 +215,16 @@ void train(int dataset_type, char* images_file, char* labels_file, char* data_di
         // du multi-threading car chaque copie du réseau initiale sera légèrement différente
         // et donnera donc des résultats différents sur les mêmes images.
         accuracy = 0.;
+        loss = 0.;
         knuth_shuffle(shuffle_index, nb_images_total);
         batches_epoques = div_up(nb_images_total, BATCHES);
         nb_images_total_remaining = nb_images_total;
         #ifndef USE_MULTITHREADING
             train_params->nb_images = BATCHES;
         #endif
+
         for (int j=0; j < batches_epoques; j++) {
+            batch_loss = 0.;
             #ifdef USE_MULTITHREADING
                 if (j == batches_epoques-1) {
                     nb_remaining_images = nb_images_total_remaining;
@@ -241,14 +258,16 @@ void train(int dataset_type, char* images_file, char* labels_file, char* data_di
                     if (train_parameters[k]->network) {
                         pthread_join( tid[k], NULL );
                         accuracy += train_parameters[k]->accuracy / (float) nb_images_total;
+                        loss += train_parameters[k]->loss/nb_images_total;
+                        batch_loss += train_parameters[k]->loss/BATCHES;
                     }
                 }
 
                 // On attend que tous les fils aient fini avant d'appliquer des modifications au réseau principal
                 for (int k=0; k < nb_threads; k++) {
                     if (train_parameters[k]->network) { // Si le fil a été utilisé
-                        update_weights(network, train_parameters[k]->network, train_parameters[k]->nb_images);
-                        update_bias(network, train_parameters[k]->network, train_parameters[k]->nb_images);
+                        update_weights(network, train_parameters[k]->network);
+                        update_bias(network, train_parameters[k]->network);
                         free_network(train_parameters[k]->network);
                     }
                 }
@@ -269,13 +288,18 @@ void train(int dataset_type, char* images_file, char* labels_file, char* data_di
 
                 accuracy += train_params->accuracy / (float) nb_images_total;
                 current_accuracy = accuracy * nb_images_total/((j+1)*BATCHES);
+                loss += train_params->loss/nb_images_total;
+                batch_loss += train_params->loss/BATCHES;
 
-                update_weights(network, network, train_params->nb_images);
-                update_bias(network, network, train_params->nb_images);
+                update_weights(network, network);
+                update_bias(network, network);
 
                 printf("\rÉpoque [%d/%d]\tImage [%d/%d]\tAccuracy: "YELLOW"%0.4f%%"RESET" ", i, epochs, BATCHES*(j+1), nb_images_total, current_accuracy*100);
                 fflush(stdout);
             #endif
+            // Il serait intéressant d'utiliser la perte calculée pour
+            // savoir l'avancement dans l'apprentissage et donc comment adapter le taux d'apprentissage
+            //network->learning_rate = 0.01*batch_loss;
         }
         end_time = omp_get_wtime();
         elapsed_time = end_time - start_time;
diff --git a/src/cnn/update.c b/src/cnn/update.c
index bd47e73..c2c61aa 100644
--- a/src/cnn/update.c
+++ b/src/cnn/update.c
@@ -3,7 +3,7 @@
 #include "include/update.h"
 #include "include/struct.h"
 
-void update_weights(Network* network, Network* d_network, int nb_images) {
+void update_weights(Network* network, Network* d_network) {
     int n = network->size;
     int input_depth, input_width, output_depth, output_width, k_size;
     Kernel* k_i;
@@ -24,7 +24,7 @@ void update_weights(Network* network, Network* d_network, int nb_images) {
                 for (int b=0; b<output_depth; b++) {
                     for (int c=0; c<k_size; c++) {
                         for (int d=0; d<k_size; d++) {
-                            cnn->w[a][b][c][d] -= (network->learning_rate/nb_images) * d_cnn->d_w[a][b][c][d];
+                            cnn->w[a][b][c][d] -= network->learning_rate * d_cnn->d_w[a][b][c][d];
                             d_cnn->d_w[a][b][c][d] = 0;
                         }
                     }
@@ -36,7 +36,7 @@ void update_weights(Network* network, Network* d_network, int nb_images) {
                 Kernel_nn* d_nn = dk_i->nn;
                 for (int a=0; a<input_width; a++) {
                     for (int b=0; b<output_width; b++) {
-                        nn->weights[a][b] -= (network->learning_rate/nb_images) * d_nn->d_weights[a][b];
+                        nn->weights[a][b] -= network->learning_rate * d_nn->d_weights[a][b];
                         d_nn->d_weights[a][b] = 0;
                     }
                 }
@@ -46,7 +46,7 @@ void update_weights(Network* network, Network* d_network, int nb_images) {
                 int input_size = input_width*input_width*input_depth;
                 for (int a=0; a<input_size; a++) {
                     for (int b=0; b<output_width; b++) {
-                        nn->weights[a][b] -= (network->learning_rate/nb_images) * d_nn->d_weights[a][b];
+                        nn->weights[a][b] -= network->learning_rate * d_nn->d_weights[a][b];
                         d_nn->d_weights[a][b] = 0;
                     }
                 }
@@ -57,7 +57,7 @@ void update_weights(Network* network, Network* d_network, int nb_images) {
     }
 }
 
-void update_bias(Network* network, Network* d_network, int nb_images) {
+void update_bias(Network* network, Network* d_network) {
 
     int n = network->size;
     int output_width, output_depth;
@@ -75,7 +75,7 @@ void update_bias(Network* network, Network* d_network, int nb_images) {
             for (int a=0; a<output_depth; a++) {
                 for (int b=0; b<output_width; b++) {
                     for (int c=0; c<output_width; c++) {
-                        cnn->bias[a][b][c] -= (network->learning_rate/nb_images) * d_cnn->d_bias[a][b][c];
+                        cnn->bias[a][b][c] -= network->learning_rate * d_cnn->d_bias[a][b][c];
                         d_cnn->d_bias[a][b][c] = 0;
                     }
                 }
@@ -84,7 +84,7 @@ void update_bias(Network* network, Network* d_network, int nb_images) {
             Kernel_nn* nn = k_i->nn;
             Kernel_nn* d_nn = dk_i->nn;
             for (int a=0; a<output_width; a++) {
-                nn->bias[a] -= (network->learning_rate/nb_images) * d_nn->d_bias[a];
+                nn->bias[a] -= network->learning_rate * d_nn->d_bias[a];
                 d_nn->d_bias[a] = 0;
             }
         } else { // Pooling