diff --git a/public/battery/generic.png b/public/battery/generic.png
new file mode 100644
index 00000000..9a9f71e6
Binary files /dev/null and b/public/battery/generic.png differ
diff --git a/src/Controller/APIController.php b/src/Controller/APIController.php
index 15b979c1..75a73184 100644
--- a/src/Controller/APIController.php
+++ b/src/Controller/APIController.php
@@ -11,6 +11,7 @@ use Symfony\Component\HttpFoundation\Response;
 use Symfony\Bundle\FrameworkBundle\Controller\Controller;
 use Symfony\Component\HttpFoundation\JsonResponse;
 use Symfony\Component\Dotenv\Dotenv;
+use Symfony\Component\HttpFoundation\RequestStack;
 
 use CrEOF\Spatial\PHP\Types\Geometry\Point;
 
@@ -2758,9 +2759,11 @@ class APIController extends Controller implements LoggedController
         if ($res->isError())
             return $res->getReturnResponse();
 
+        /*
         // initialize data
         $data = [
             'is_valid' => false,
+            'is_registered' => false,
             'customer' => [
                 'first_name' => '',
                 'last_name' => '',
@@ -2772,6 +2775,7 @@ class APIController extends Controller implements LoggedController
                 'size' => '',
             ],
         ];
+        */
 
         // check if warranty serial is there
         $warr_serial = $em->getRepository(WarrantySerial::class)->find($serial);
@@ -2779,6 +2783,13 @@ class APIController extends Controller implements LoggedController
         $batt = null;
         $is_registered = false;
 
+        if ($warr_serial == null)
+        {
+            $res->setError(true)
+                ->setErrorMessage('Invalid warranty serial code.');
+            return $res->getReturnResponse();
+        }
+
         // if warranty serial is there
         if ($warr_serial != null)
         {
@@ -2786,10 +2797,17 @@ class APIController extends Controller implements LoggedController
             if ($warr != null)
             {
                 $is_registered = true;
+
+                // null mobile number should be blank string instead
+                if ($warr->getMobileNumber() == null)
+                    $mobile_num = '';
+                else 
+                    $mobile_num = $warr->getMobileNumber();
+
                 $customer = [
                     'first_name' => $warr->getFirstName(),
                     'last_name' => $warr->getLastName(),
-                    'mobile_number' => $warr->getMobileNumber(),
+                    'mobile_number' => $mobile_num,
                     'plate_number' => $warr->getPlateNumber(),
                 ];
             }
@@ -2805,11 +2823,14 @@ class APIController extends Controller implements LoggedController
 
             $sku = $warr_serial->getSKU();
             $batt = $em->getRepository(SAPBattery::class)->find($sku);
+            // TODO: put this in a config file
+            $image_url = $req->getSchemeAndHttpHost() . '/battery/generic.png';
             if ($batt != null)
             {
                 $battery = [
                     'brand' => $batt->getBrand()->getName(),
                     'size' => $batt->getSize()->getName(),
+                    'image_url' => $image_url,
                 ];
             }
             else 
@@ -2817,6 +2838,7 @@ class APIController extends Controller implements LoggedController
                 $battery = [
                     'brand' => '',
                     'size' => '',
+                    'image_url' => '',
                 ];
             }