Andrew I've used the same optimate for the last three years, 2 years on a jap bike, 1 year on the Duke. I had to replace the battery on the Duke, although I couldn't understand why as it was only 1 year old and was always connected to the optimate....! While I was in the garage getting a new battery, I was telling Andy (yellowisfriedegg) about the problem....he suggested maybe I had switched on the Optimate BEFORE I connected it to the bike as this could damage the battery.....I wasn't sure if I had or not....After fitting the new battery I always make sure it's connected first, then switch on the optimate.........Since then, I've had no problems...hope this help.... Stuart |