I have ordered a replacement battery for my 520 and am now regretting it as it looks like it is tricky to replace it. See the instructions and photos towards the bottom of the first page in this link. I thought it would be similar to replacing a camera or cell phone battery!!! http://www.pocketgpsworld.com//modules.php?name=Forums&file=viewtopic&t=72541&start=0
Good Luck
Jan, November 2010
