<p>I bought this YongNuo remote shutter release several years ago for my XSi. I didn't use it much, if at all. I now have a 650D and just found this gadget. It has the original CR2 lithium battery in it and doesn't seem to work. I can find no instruction manual either here on paper or online. I see no model number on either unit.<br /> - Does it work with only the one CR2 battery in the almost-square unit, with the other unit not having a battery (I can see no way to open that case)?<br /> - Is it worth getting a new CR2 battery for (and possibly a battery for whatever is inside the transmitter case)? Are newer ones enough better that it would be best to get a new one (they don't seem to cost much)? I'd prefer one that used commonly-available batteries (AA, AAA)<br /> All comments appreciated.<img src="http://ruthvenphotos2.com/files/IMG_1809_1000h.jpg" alt="" width="1129" height="1000" /></p>