I have used these batteries on a few items before and I am very pleased with them. they give great life when using with my Canon flash guns also on my bait boat transmitter the old Duracell would not last a full two day session at the bank these will do a four day session no problem. I always carry a spare set with me and its nice to have them in a case so they don't get lost at the bottom of my bag but to be honest I have never had call to use the spares yet.