You just set up your equipment for the first dive of your vacation in Saint Somewhere, as you press the activation button on your dive computer it goes through the diagnostic screen and what do you see the "Low Batt" Icon appears. The worst thing that can happen on a tropical vacation has just happen No Dive Computer. Don"t leave on a vacation without a spare battery kit, why ruin a great holiday because of a few dollars in batteries.If you"re planning a Dive Vacation this is a must for your Save-a-Dive Kit. Avoid Island prices.