http://cgi.ebay.com/Fast-Smart-Charg...item51922e6378
I have been using that model (with tempeture sensor & voltage control) for about a year... mine has 7,2 v to 14,x v
Works for me... not sure but my understanding is that what kills batteries is hi temperatures caused by over charge... this one slows down if the temperature rises..
Cheer,
(I've heard the batery killer comments... but not for the temp. sensor one...
Pete