Notice: Undefined index: driver in Database::openConnection() when trying to connect to sqlite db
The documentation is a bit misguiding as it states that the database array should be identical to the way it is declared on the settings.php file. This is wrong! 

After digging a little bit the core module it shows that addConnectionInfo is expecting a array that defines the database and the driver.

Here is the correct implementation:

      $module_path = drupal_get_path('module', 'cw_ticketing' );
      $db1 = array (
        'database' =&gt; $module_path.'/247cinema_part1.sqlite',
        'driver' =&gt; 'sqlite',
      );
      $db2 = array (
        'database' =&gt; $module_path.'/247cinema_part2.sqlite',
        'driver' =&gt; 'sqlite',
      );
      // die(var_dump($databases));
      Database::addConnectionInfo('247', 'db1', $db1);
      Database::addConnectionInfo('247', 'db2', $db2);