Props trajche.

wc_register_order_type(
	'shop_order_charge',
	array(
		'label'                            => __( 'Charges', 'woocommerce' ),
		'capability_type'                  => 'shop_order',
		'public'                           => true,
		'hierarchical'                     => true,
		'exclude_from_orders_screen'       => false,
		'add_order_meta_boxes'             => true,
		'exclude_from_order_count'         => true,
		'exclude_from_order_views'         => false,
		'exclude_from_order_reports'       => false,
		'exclude_from_order_sales_reports' => false,
		'class_name'                       => 'WC_Order_Charge',
		'supports'                         => array( 'title' ),
		'rewrite'                          => true,
	)
);

class WC_Order_Charge extends WC_Order {

	protected $object_type = 'order_charge';

	public function get_type() {
		return 'shop_order_charge';
	}
}