I am using several ac adapters, which I modified for use with the eDGe. They are all just 12V adapters, all very small about the same size as the iPhone AC adapter, but have different current ratings (1A) than the one supplied with the eDGe (2.5A). I have absolutely no problems with them at all. No adverse effects at all. I have never noticed any differences with the battery life in any way. The problem is the tip that the eDGe uses. Thats why I modified it myself. Now I have multiple adapters, all nice and small, that I can easily carry around with my eDGe.