Anyone have any experience with something like this? it seems like this would be a useful tool so that you dont fry your amp if voltage gets too low
http://www.cadencestore.com/ProductCart/pc/viewPrd.asp?idcategory=144&idproduct=447
http://www.cadencestore.com/ProductCart/pc/viewPrd.asp?idcategory=144&idproduct=447