I bought a relatively expensive thick cable which promised a higher charging speed but the micro USB plug doesn't seem to fit into the Surface 3. It's a small/thin plug too (i.e. it's not huge/chunky or anything). It fits into my Samsung Galaxy Tab S and my Sony BT50 headphones for charging fine so I'm not quite sure why it just won't fit in fully into the S3. It goes in a little but seems to get stuck before it's fully in. Windows recognises it's charging sortof but then it drops out.