POST a form array without successful

Question

You need to generate the controls for the collection in a for loop so they are correctly named with indexers (note that property BatchProducts needs to be IList<BatchProductViewModel>

@using (Html.BeginForm("Save", "ConnectBatchProduct", FormMethod.Post))
{
  ....
  <table>
    ....
    @for(int i = 0; i < Model.BatchProducts.Count; i++)
    {
      <tr>
        <td>@Html.TextBoxFor(m => m.BatchProducts[i].Quantity)</td>
        <td>@Html.TextBoxFor(m => m.BatchProducts[i].BatchName)</td>
        <td>
          // add the following to allow for dynamically deleting items in the view
          <input type="hidden" name="BatchProducts.Index" value="@i" />
          <a class="deleteRow"></a>
        </td>
      </tr>
    }
    ....
  </table>
  ....
}

Then the POST method needs to be

public ActionResult Save(ConnectBatchProductViewModel model)
{
  ....
}

Edit

Note: Further to your edit, if you want to dynamically add and remove BatchProductViewModel items in he view, you will need to use the BeginCollectionItem helper or a html template as discussed in this answer

The template to dynamically add new items would be

<div id="NewBatchProduct" style="display:none">
  <tr>
    <td><input type="text" name="BatchProducts[#].Quantity" value /></td>
    <td><input type="text" name="BatchProducts[#].BatchName" value /></td>
    <td>
      <input type="hidden" name="BatchProducts.Index" value ="%"/>
      <a class="deleteRow"></a>
    </td>
  </tr>
</div>

Note the dummy indexers and the non-matching value for the hidden input prevents this template posting back.

Then the script to add a new BatchProducts would be

$("#addrow").click(function() {
  var index = (new Date()).getTime(); // unique indexer
  var clone = $('#NewBatchProduct').clone(); // clone the BatchProducts item
  // Update the index of the clone
  clone.html($(clone).html().replace(/\[#\]/g, '[' + index + ']'));
  clone.html($(clone).html().replace(/"%"/g, '"' + index  + '"'));
  $("table.order-list").append(clone.html());
});