# Calculate battery duration [duplicate]

Maybe this is a trivial question, but I am struggling with it for a while.

I have an alkaline AA battery which is consuming 80mA for 8 seconds each 30 minutes. I need to calculate how many days it will last before reaching 1.1v. I know it depends a lot on the battery type, but let's say it is a Duracell battery.

I have problems in calculating the "average" consumption per hour, as the battery is drained for just 8 seconds (80mA) each 30 minutes.

Thanks for any help.

## marked as duplicate by Marcus Müller, Andy aka, Leon Heller, winny, MapleAug 26 '18 at 3:59

• @ Fabio This is an energy question. Compute the energy consumed each hour. (ampseconds). And examine the typical amphours of your chosen battery size (e.g 1 amp*hour). – analogsystemsrf Aug 25 '18 at 16:17
• Yes, thanks. But this would give me time to discharge. I need to compute "time to 1.1 volts"... – Fabio Marzocca Aug 26 '18 at 9:30

$$I_{AVG} = \frac {80m \times 8}{30 \times 60} = 0.35 \ \text {mA}$$