Style "more.." link while using the_content_feed

I am trying create a page of multiple posts that automatically adds a “read more..” after a specific number of characters, while including images and using css to style the “read more…” link.

In searching I ran across a suggestion to use the_content_rss which has now been replaced with the_content_feed. It solves automatically adding “read more…” and including images. The issue is that I can not change the text or style of the “read more…” that appears with the_content_feed. I used this to stylize my “read more..” when implementing the_content : the_content('<div id="readmore">Read More ></div>');

This does not work when using:the_content_feed('<div id="readmore">Read More ></div>');

1. Is there a way to make this work using the_content_feed?
or
2. Is there a better way to solve the initial issue?

Thanks