diff --git a/dev/Untitled1.ipynb b/dev/Untitled1.ipynb
index 72e691e6..762517d1 100644
--- a/dev/Untitled1.ipynb
+++ b/dev/Untitled1.ipynb
@@ -80,13 +80,6 @@
       "- Extracting source database\n",
       "- Extracting inventories\n",
       "- Fetching IAM data\n",
-      "dict_items([('train, electric', 'ES|Transport|Freight|Rail|Electric'), ('train, diesel-electric', ['ES|Transport|Freight|Rail|Liquids|Fossil', 'ES|Transport|Freight|Rail|Liquids|Biomass']), ('train, fuel cell', 'ES|Transport|Freight|Rail|Liquids|Hydrogen')])\n",
-      "1113 set()\n",
-      "1113 set()\n",
-      "1113 set()\n",
-      "1113 set()\n",
-      "1113 set()\n",
-      "1113 set()\n",
       "Done!\n"
      ]
     }
@@ -112,35 +105,83 @@
   {
    "cell_type": "code",
    "execution_count": 5,
-   "id": "3e88c655-ddb1-409d-b84f-c2c4e1976542",
+   "id": "0c80994c-cbac-4143-81ee-1de1531a6f95",
    "metadata": {},
    "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "Processing scenarios: 100%|█████████████| 1/1 [01:37<00:00, 97.61s/it]"
+     ]
+    },
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "Generate scenario report.\n",
-      "Report saved under /Users/romain/GitHub/premise/dev/export/scenario_report.\n"
+      "Done!\n",
+      "\n"
+     ]
+    },
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "\n"
      ]
     }
    ],
    "source": [
-    "ndb.generate_scenario_report()"
+    "ndb.update()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "id": "0c80994c-cbac-4143-81ee-1de1531a6f95",
+   "execution_count": 6,
+   "id": "3b0e71e7-2fbb-4247-abcf-60ebb1909d4a",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "gearbox, for lorry 201.6\n",
+      "transmission, for lorry 291.2\n",
+      "treatment of used lorry, 40 metric ton -1\n",
+      "market for power distribution unit, for electric passenger car 4\n",
+      "assembly operation, for lorry 29223.50287857302\n",
+      "market for converter, for electric passenger car 25\n",
+      "market for inverter, for electric passenger car 41.19999946653843\n",
+      "suspension, for lorry 3440\n",
+      "power electronics, for lorry 265\n",
+      "tires and wheels, for lorry 1422\n",
+      "market for battery management system, for Li-ion battery 125.73132358067981\n",
+      "glider lightweighting 268.7599962415552\n",
+      "cabin, for lorry 1153\n",
+      "other components, for electric lorry 1059\n",
+      "maintenance, lorry 40 metric ton 1\n",
+      "frame, blanks and saddle, for lorry 5539\n",
+      "market for electric motor, electric passenger car 600\n",
+      "market for used Li-ion battery -314.32832768712774\n",
+      "retarder, for lorry 67.2\n",
+      "market for battery cell, Li-ion, NMC622 188.597004106448\n",
+      "heavy duty truck, battery electric, NMC-622 battery, 40t gross weight, long haul 1\n"
+     ]
+    }
+   ],
    "source": [
-    "ndb.update()"
+    "from premise.utils import load_database\n",
+    "ndb.scenarios[0] = load_database(ndb.scenarios[0])\n",
+    "\n",
+    "for ds in ndb.scenarios[0][\"database\"]:\n",
+    "    if ds[\"name\"] == \"heavy duty truck, battery electric, NMC-622 battery, 40t gross weight, long haul\":\n",
+    "        for e in ds[\"exchanges\"]:\n",
+    "            print(e[\"name\"], e[\"amount\"])"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 6,
    "id": "dff4efb1-69ab-4bd5-8d52-4038df180a85",
    "metadata": {},
    "outputs": [
@@ -159,7 +200,7 @@
      "text": [
       "Writing activities to SQLite3 database:\n",
       "0% [##############################] 100% | ETA: 00:00:00\n",
-      "Total time elapsed: 00:00:32\n"
+      "Total time elapsed: 00:00:28\n"
      ]
     },
     {
@@ -167,16 +208,21 @@
      "output_type": "stream",
      "text": [
       "Title: Writing activities to SQLite3 database:\n",
-      "  Started: 07/01/2024 17:19:47\n",
-      "  Finished: 07/01/2024 17:20:20\n",
-      "  Total time elapsed: 00:00:32\n",
-      "  CPU %: 94.20\n",
-      "  Memory %: 15.94\n"
+      "  Started: 07/11/2024 21:39:26\n",
+      "  Finished: 07/11/2024 21:39:54\n",
+      "  Total time elapsed: 00:00:28\n",
+      "  CPU %: 92.10\n",
+      "  Memory %: 19.69\n",
+      "Created database: trspt 4\n",
+      "Generate scenario report.\n",
+      "Report saved under /Users/romain/GitHub/premise/dev/export/scenario_report.\n",
+      "Generate change report.\n",
+      "Report saved under /Users/romain/GitHub/premise/dev.\n"
      ]
     }
    ],
    "source": [
-    "ndb.write_db_to_brightway()"
+    "ndb.write_db_to_brightway(\"trspt 4\")"
    ]
   },
   {
diff --git a/premise/activity_maps.py b/premise/activity_maps.py
index 5b435767..3023ef69 100644
--- a/premise/activity_maps.py
+++ b/premise/activity_maps.py
@@ -275,54 +275,66 @@ def generate_transport_map(self, transport_type: str) -> dict:
         Rerurns a dictionary with transport type as keys (see below) and
         a set of related ecoinvent activities' names as values.
         """
+        mapping = {}
         if transport_type == "car":
-            return self.generate_sets_from_filters(
-                get_mapping(filepath=PASSENGER_CARS, var="ecoinvent_aliases")
+            mapping = self.generate_sets_from_filters(
+                get_mapping(filepath=PASSENGER_CARS, var="ecoinvent_aliases", model=self.model)
             )
         elif transport_type == "two-wheeler":
-            return self.generate_sets_from_filters(
-                get_mapping(filepath=TWO_WHEELERS, var="ecoinvent_aliases")
+            mapping = self.generate_sets_from_filters(
+                get_mapping(filepath=TWO_WHEELERS, var="ecoinvent_aliases", model=self.model)
             )
         elif transport_type == "bus":
-            return self.generate_sets_from_filters(
-                get_mapping(filepath=BUSES, var="ecoinvent_aliases")
+            mapping = self.generate_sets_from_filters(
+                get_mapping(filepath=BUSES, var="ecoinvent_aliases", model=self.model)
             )
         elif transport_type == "truck":
-            return self.generate_sets_from_filters(
-                get_mapping(filepath=TRUCKS, var="ecoinvent_aliases")
+            mapping = self.generate_sets_from_filters(
+                get_mapping(filepath=TRUCKS, var="ecoinvent_aliases", model=self.model)
             )
         elif transport_type == "train":
-            return self.generate_sets_from_filters(
-                get_mapping(filepath=TRAINS, var="ecoinvent_aliases")
+            mapping = self.generate_sets_from_filters(
+                get_mapping(filepath=TRAINS, var="ecoinvent_aliases", model=self.model)
             )
 
+        # remove empty values
+        mapping = {key: val for key, val in mapping.items() if len(val) > 0}
+
+        return mapping
+
     def generate_vehicle_fuel_map(self, transport_type: str) -> dict:
         """
         Filter ecoinvent processes related to transport fuels.
         Rerurns a dictionary with transport type as keys (see below) and
         a set of related ecoinvent activities' names as values.
         """
+        mapping = {}
         if transport_type == "car":
-            return self.generate_sets_from_filters(
+            mapping = self.generate_sets_from_filters(
                 get_mapping(filepath=PASSENGER_CARS, var="ecoinvent_fuel_aliases")
             )
         elif transport_type == "two-wheeler":
-            return self.generate_sets_from_filters(
+            mapping = self.generate_sets_from_filters(
                 get_mapping(filepath=TWO_WHEELERS, var="ecoinvent_fuel_aliases")
             )
         elif transport_type == "bus":
-            return self.generate_sets_from_filters(
+            mapping = self.generate_sets_from_filters(
                 get_mapping(filepath=BUSES, var="ecoinvent_fuel_aliases")
             )
         elif transport_type == "truck":
-            return self.generate_sets_from_filters(
+            mapping = self.generate_sets_from_filters(
                 get_mapping(filepath=TRUCKS, var="ecoinvent_fuel_aliases")
             )
         elif transport_type == "train":
-            return self.generate_sets_from_filters(
+            mapping = self.generate_sets_from_filters(
                 get_mapping(filepath=TRAINS, var="ecoinvent_fuel_aliases")
             )
 
+        # remove empty values
+        mapping = {key: val for key, val in mapping.items() if len(val) > 0}
+
+        return mapping
+
     def generate_sets_from_filters(self, filtr: dict, database=None) -> dict:
         """
         Generate a dictionary with sets of activity names for
diff --git a/premise/battery.py b/premise/battery.py
new file mode 100644
index 00000000..ac04a371
--- /dev/null
+++ b/premise/battery.py
@@ -0,0 +1,157 @@
+"""
+module to adjust the battery inputs to reflect progress in
+terms of cell energy density.
+
+"""
+
+import yaml
+
+from .logger import create_logger
+from .transformation import (
+    BaseTransformation,
+    IAMDataCollection,
+    List,
+    np,
+    ws,
+)
+from .filesystem_constants import DATA_DIR
+
+logger = create_logger("battery")
+
+
+def load_cell_energy_density():
+    """
+    Load cell energy density data.
+    """
+    with open(DATA_DIR / "battery/energy_density.yaml", "r") as file:
+        data = yaml.load(file, Loader=yaml.FullLoader)
+
+    return {x["ecoinvent_aliases"]["name"]: x["target"] for x in data.values()}
+
+
+def _update_battery(scenario, version, system_model):
+    battery = Battery(
+        database=scenario["database"],
+        iam_data=scenario["iam data"],
+        model=scenario["model"],
+        pathway=scenario["pathway"],
+        year=scenario["year"],
+        version=version,
+        system_model=system_model,
+        cache=scenario.get("cache"),
+        index=scenario.get("index"),
+    )
+
+    battery.adjust_battery_mass()
+
+    scenario["database"] = battery.database
+    scenario["index"] = battery.index
+    scenario["cache"] = battery.cache
+
+    return scenario
+
+
+class Battery(BaseTransformation):
+    """
+    Class that modifies the battery market to reflect progress
+    in terms of cell energy density.
+
+    """
+
+    def __init__(
+        self,
+        database: List[dict],
+        iam_data: IAMDataCollection,
+        model: str,
+        pathway: str,
+        year: int,
+        version: str,
+        system_model: str,
+        cache: dict = None,
+        index: dict = None,
+    ) -> None:
+        super().__init__(
+            database,
+            iam_data,
+            model,
+            pathway,
+            year,
+            version,
+            system_model,
+            cache,
+            index,
+        )
+        self.system_model = system_model
+
+    def adjust_battery_mass(self) -> None:
+        """
+        Adjust vehicle components (e.g., battery).
+        Adjust the battery mass to reflect progress in battery technology.
+        Specifically, we adjust the battery mass to reflect progress in
+        terms of cell energy density.
+        We leave the density unchanged after 2050.
+        """
+
+        energy_density = load_cell_energy_density()
+
+        filters = [
+            ws.contains("name", x)
+            for x in energy_density
+        ]
+
+        for ds in ws.get_many(
+            self.database,
+            ws.exclude(
+                ws.either(
+                    *[
+                        ws.contains("name", x)
+                        for x in [
+                            "market for battery",
+                            "battery production",
+                            "battery cell production",
+                            "cell module production",
+                        ]
+                    ]
+                )
+            ),
+        ):
+
+            for exc in ws.technosphere(
+                ds, ws.either(*filters)
+            ):
+                name = [x for x in energy_density if x in exc["name"]][0]
+
+                scaling_factor = (
+                    energy_density[name][2020] / np.clip(
+                        np.interp(
+                            self.year,
+                            list(energy_density[name].keys()),
+                            list(energy_density[name].values()),
+                        ),
+                        0.1,
+                        0.5
+                    )
+                )
+
+                if "log parameters" not in ds:
+                    ds["log parameters"] = {}
+
+                ds["log parameters"]["battery input"] = exc["name"]
+                ds["log parameters"]["old battery mass"] = exc["amount"]
+                exc["amount"] *= scaling_factor
+                ds["log parameters"]["new battery mass"] = exc["amount"]
+
+                self.write_log(ds, status="modified")
+
+    def write_log(self, dataset, status="created"):
+        """
+        Write log file.
+        """
+
+        logger.info(
+            f"{status}|{self.model}|{self.scenario}|{self.year}|"
+            f"{dataset['name']}|{dataset['location']}|"
+            f"{dataset.get('log parameters', {}).get('battery input', '')}|"
+            f"{dataset.get('log parameters', {}).get('old battery mass', '')}|"
+            f"{dataset.get('log parameters', {}).get('new battery mass', '')}"
+        )
diff --git a/premise/data/battery/energy_density.yaml b/premise/data/battery/energy_density.yaml
new file mode 100644
index 00000000..7a43f234
--- /dev/null
+++ b/premise/data/battery/energy_density.yaml
@@ -0,0 +1,65 @@
+# Battery cell energy densities, in kWh/kg cell
+---
+
+Li-ion:
+  ecoinvent_aliases:
+    name: market for battery, Li-ion
+  target:
+    2020: 0.2
+    2050: 0.5
+
+NMC111:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, NMC111
+  target:
+    2020: 0.2
+    2050: 0.5
+
+NMC622:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, NMC622
+  target:
+    2020: 0.2
+    2050: 0.5
+
+NMC811:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, NMC811
+  target:
+    2020: 0.2
+    2050: 0.5
+
+NCA:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, NCA
+  target:
+      2020: 0.2
+      2050: 0.5
+
+LFP:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, LFP
+  target:
+      2020: 0.2
+      2050: 0.5
+
+LTO:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, LTO
+  target:
+      2020: 0.2
+      2050: 0.5
+
+LiMn2O4:
+  ecoinvent_aliases:
+    name: market for battery cell, Li-ion, LiMn2O4
+  target:
+      2020: 0.2
+      2050: 0.5
+
+BoP:
+  ecoinvent_aliases:
+    name: market for battery management system
+  target:
+      2020: 0.2
+      2050: 0.5
diff --git a/premise/data/utils/logging/logconfig.yaml b/premise/data/utils/logging/logconfig.yaml
index 0037baa8..a4b328c8 100644
--- a/premise/data/utils/logging/logconfig.yaml
+++ b/premise/data/utils/logging/logconfig.yaml
@@ -72,6 +72,14 @@ handlers:
     formatter: simple
     mode: a
 
+  file_battery:
+    class: logging.FileHandler
+    level: INFO
+    filename: "export/logs/premise_battery.log"
+    encoding: utf8
+    formatter: simple
+    mode: a
+
   file_transport:
     class: logging.FileHandler
     level: INFO
@@ -140,6 +148,11 @@ loggers:
     handlers: [ file_fuel ]
     propagate: False
 
+  battery:
+    level: INFO
+    handlers: [ file_battery ]
+    propagate: False
+
   heat:
     level: INFO
     handlers: [ file_heat ]
diff --git a/premise/data/utils/logging/reporting.yaml b/premise/data/utils/logging/reporting.yaml
index 74392c39..c13e23cc 100644
--- a/premise/data/utils/logging/reporting.yaml
+++ b/premise/data/utils/logging/reporting.yaml
@@ -462,6 +462,49 @@ premise_heat:
         unit: kg CO2/reference flow
     tab: Heat
 
+premise_battery:
+    columns:
+      timestamp:
+        name: timestamp
+        description: Timestamp of the log entry
+      module:
+        name: module
+        description: Module name
+      level:
+        name: level
+        description: Log level
+      status:
+        name: status
+        description: Status of the dataset
+      model:
+        name: model
+        description: IAM model name
+      pathway:
+        name: pathway
+        description: Pathway name
+      year:
+        name: year
+        description: Year
+      dataset:
+        name: dataset
+        description: Dataset name
+      region:
+        name: region
+        description: Region name
+      battery input:
+        name: Battery provider
+        description: Name of the battery provider
+        unit: unitless
+      old battery mass:
+        name: Old battery mass
+        description: Mass of the battery before adjustment
+        unit: kg
+      new battery mass:
+        name: New battery mass
+        description: Mass of the battery after adjustment
+        unit: kg
+    tab: Battery
+
 premise_transport:
     columns:
       timestamp:
diff --git a/premise/iam_variables_mapping/transport_roadfreight_variables.yaml b/premise/iam_variables_mapping/transport_roadfreight_variables.yaml
index bcf6be71..07f1d483 100644
--- a/premise/iam_variables_mapping/transport_roadfreight_variables.yaml
+++ b/premise/iam_variables_mapping/transport_roadfreight_variables.yaml
@@ -132,7 +132,6 @@ truck, fuel cell electric, 18t:
     fltr:
       - hydrogen
 
-
 truck, diesel, 18t:
   iam_aliases:
     remind: ES|Transport|Freight|Road|Truck (18t)|Liquids
diff --git a/premise/new_database.py b/premise/new_database.py
index 33ec9267..6be589af 100644
--- a/premise/new_database.py
+++ b/premise/new_database.py
@@ -22,6 +22,7 @@
 from .data_collection import IAMDataCollection
 from .direct_air_capture import _update_dac
 from .electricity import _update_electricity
+from .battery import _update_battery
 from .emissions import _update_emissions
 from .export import (
     Export,
@@ -867,6 +868,7 @@ def update(self, sectors: [str, list, None] = None) -> None:
             "steel": {"func": _update_steel, "args": (self.version, self.system_model)},
             "fuels": {"func": _update_fuels, "args": (self.version, self.system_model)},
             "heat": {"func": _update_heat, "args": (self.version, self.system_model)},
+            "battery": {"func": _update_battery, "args": (self.version, self.system_model)},
             "emissions": {
                 "func": _update_emissions,
                 "args": (self.version, self.system_model, self.gains_scenario),
diff --git a/premise/report.py b/premise/report.py
index 5073cf15..fbc89ba1 100644
--- a/premise/report.py
+++ b/premise/report.py
@@ -568,6 +568,7 @@ def generate_change_report(source, version, source_type, system_model):
         "premise_electricity",
         "premise_fuel",
         "premise_heat",
+        "premise_battery",
         "premise_transport",
         "premise_steel",
         "premise_metal",
diff --git a/premise/transport.py b/premise/transport.py
index 8eb36c08..749ed658 100644
--- a/premise/transport.py
+++ b/premise/transport.py
@@ -10,6 +10,7 @@
 import xarray as xr
 import yaml
 from wurst import searching as ws
+import numpy as np
 
 from .activity_maps import InventorySet
 from .filesystem_constants import DATA_DIR, IAM_OUTPUT_DIR
@@ -29,7 +30,6 @@
 
 
 def _update_vehicles(scenario, vehicle_type, version, system_model):
-
     has_fleet = False
     if vehicle_type == "car":
         if hasattr(scenario["iam data"], "passenger_car_markets"):
@@ -485,14 +485,13 @@ def create_vehicle_markets(self) -> list:
                         if (name, loc) in list_created_trucks:
                             exc["name"] = name
                         else:
-                            exc["name"] = (
-                                f"transport, freight, lorry, unspecified, long haul"
-                            )
-
+                            exc[
+                                "name"
+                            ] = f"transport, freight, lorry, unspecified, long haul"
                     else:
-                        exc["name"] = (
-                            "transport, freight, lorry, unspecified, long haul"
-                        )
+                        exc[
+                            "name"
+                        ] = "transport, freight, lorry, unspecified, long haul"
 
                     exc["product"] = "transport, freight, lorry"
                     exc["location"] = self.geo.ecoinvent_to_iam_location(
@@ -552,6 +551,7 @@ def adjust_transport_efficiency(self, dataset):
 
         return dataset
 
+
     def write_log(self, dataset, status="created"):
         """
         Write log file.