diff --git a/config/routes/capi_rider.yaml b/config/routes/capi_rider.yaml
index 6ef2e92a..8fc40654 100644
--- a/config/routes/capi_rider.yaml
+++ b/config/routes/capi_rider.yaml
@@ -94,3 +94,9 @@ capi_rider_jo_start:
     path: /rider_api/start
     controller: App\Controller\CAPI\RiderAppController::startJobOrder
     methods: [POST]
+
+# trade-ins
+capi_rider_battery_sizes:
+    path: /rider_api/battery_sizes
+    controller: App\Controller\CAPI\RiderAppController::getBatterySizes
+    methods: [GET]
\ No newline at end of file
diff --git a/src/Controller/CAPI/RiderAppController.php b/src/Controller/CAPI/RiderAppController.php
index d29f6a04..ea3128fd 100644
--- a/src/Controller/CAPI/RiderAppController.php
+++ b/src/Controller/CAPI/RiderAppController.php
@@ -758,6 +758,33 @@ class RiderAppController extends ApiController
        return new APIResponse(true, 'Rider arrive at hub.', $data);
     }
 
+    public function getBatterySizes(Request $req, EntityManagerInterface $em)
+    {
+        // get capi user
+        $capi_user = $this->getUser();
+        if ($capi_user == null)
+            return new APIResponse(false, 'User not found.');
+
+        // get rider id from capi user metadata
+        $rider = $this->getRiderFromCAPI($capi_user, $em);
+        if ($rider == null)
+            return new APIResponse(false, 'No rider found.');
+
+        // get sizes
+        $qb = $em->getRepository(BatterySize::class)
+            ->createQueryBuilder('bs');
+
+        $sizes = $qb->select('bs.id, bs.name')
+            ->orderBy('bs.name', 'asc')
+            ->getQuery()
+            ->getResult();
+
+        // response
+        return new APIResponse(true, '', [
+            'sizes' => $sizes,
+        ]);
+    }
+
     public function payment(Request $req, EntityManagerInterface $em, JobOrderHandlerInterface $jo_handler,
                             RisingTideGateway $rt, WarrantyHandler $wh, MQTTClient $mclient, MQTTClientApiv2 $mclientv2, FCMSender $fcmclient, TranslatorInterface $translator)
     {