I lost 180lbs and during that time they replaced it. It move sideways and stayed that way. It drove me crazy. The Neurologist and surgeon both told me the same thing. My original vns was much bigger and the new one was much smaller. So they do move around in the hole mode for the original one. Well when this battery was dieing he ordered the new larger version so it doesn't move around. Now my only problem is the scar and vns have moved down my chest some. I am at my goal weight but I cant see getting a mammogram again on that side. I also have pain in the side of my neck if I lay on my left side. They assured me there is plenty of slack in the leads and I have nothing to worry about. Yeah I tell that to myself but I don't know if l believe it.