Duracell Ultra Power AA – Pack of 4. Duracell Ultra Power alkaline AA batteries have up to 100% more power. Powercheck allows you to check remaining power at a glance. Avoiding unnecessary interruptions. While Duralock Power Preserve technology keeps unused batteries fresh and powered for up to 10 years in ambient storage. To see how much power is left inside your battery, press the white dots. For our full range of batteries, click here. If you need any product advice then please give us a call on 01621 828882 and our sales team will be happy to help. We also supply Duracell indsutrial batteries, click here.