What were you using the duralites in? Electric planes under a high load? How did you charge them? I had 2, 6.0v 1800mah in a couple fun fly's to cut down on weight (I saved about 4oz). They lasted me 2 years and just died last fall. For me that's as long of a life as any nicad.. Just my experience though. Maby you got a bad run... I dunno. Sorry they craped out on you Thats a lotta $$$$$!