diff --git a/app/src/main/java/net/vonforst/evmap/storage/Database.kt b/app/src/main/java/net/vonforst/evmap/storage/Database.kt
index cf23579b..f6a7949b 100644
--- a/app/src/main/java/net/vonforst/evmap/storage/Database.kt
+++ b/app/src/main/java/net/vonforst/evmap/storage/Database.kt
@@ -22,7 +22,7 @@ import net.vonforst.evmap.viewmodel.SliderFilterValue
         Plug::class,
         Network::class,
         ChargeCard::class
-    ], version = 7
+    ], version = 8
 )
 @TypeConverters(Converters::class)
 abstract class AppDatabase : RoomDatabase() {
@@ -38,7 +38,7 @@ abstract class AppDatabase : RoomDatabase() {
             Room.databaseBuilder(context, AppDatabase::class.java, "evmap.db")
                 .addMigrations(
                     MIGRATION_2, MIGRATION_3, MIGRATION_4, MIGRATION_5, MIGRATION_6,
-                    MIGRATION_7
+                    MIGRATION_7, MIGRATION_8
                 )
                 .build()
         }
@@ -114,5 +114,11 @@ abstract class AppDatabase : RoomDatabase() {
                 db.execSQL("CREATE TABLE IF NOT EXISTS `ChargeCard` (`id` INTEGER NOT NULL, `name` TEXT NOT NULL, `url` TEXT NOT NULL, PRIMARY KEY(`id`))")
             }
         }
+
+        private val MIGRATION_8 = object : Migration(7, 8) {
+            override fun migrate(db: SupportSQLiteDatabase) {
+                db.execSQL("ALTER TABLE `ChargeLocation` ADD `chargecards` TEXT")
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/net/vonforst/evmap/storage/TypeConverters.kt b/app/src/main/java/net/vonforst/evmap/storage/TypeConverters.kt
index 01b3cb12..d4a09450 100644
--- a/app/src/main/java/net/vonforst/evmap/storage/TypeConverters.kt
+++ b/app/src/main/java/net/vonforst/evmap/storage/TypeConverters.kt
@@ -54,8 +54,8 @@ class Converters {
     }
 
     @TypeConverter
-    fun toChargeCardIdList(value: String): List<ChargeCardId>? {
-        return chargeCardIdListAdapter.fromJson(value)
+    fun toChargeCardIdList(value: String?): List<ChargeCardId>? {
+        return value?.let { chargeCardIdListAdapter.fromJson(it) }
     }
 
     @TypeConverter