Soft button-cell holders Posted on May 9, 2011May 9, 2011 by Ramyah Gowrishankar Small 3V button-cell holders made with felt and conductive thread. They are small in size and easy to sew on. Good for lighting a LED. Can use have 2 batteries stacked inside for a 6V output. Check out the “Making of” tab for step by step process for making these.