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# How to calculate battery life for specific application

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## How to calculate battery life for specific application

(OP)
Hi,

I'm trying to calculate the service life for my battery powered application.

Here's how I calculate it. Please le me know if this the right way to do this.

I'm using 3X1.5 Volts AA type alkaline batteries -put in series- (energizer titanium e2) rated at "3135mAh (down to 0.8 volts)". My application works at 4.5 volts down to 2.6 volts.

So to get the total energy from the battery I multiplied 4.5V by 3135mA by 3600 (sec) which gives about 50787 joules.

I then took the total battery energy and divided it by my application's average power consumption per day at 4.5 volts, that is about 16 joules. So 50787/16.06 = 8.6 years !!

Now I know that theorically, 8.6 years is real long for 3XAA type alkaline batteries. I would surely need to caculate the energy derating over the years.

Nevertheless, I need about 4 years of battery life. Assuming the application is used at 23 degC ambient, will this do it ?

May I use the manufacturer rated energy this way ? Thanks for helping me. I'm no battery experts and my caculation results seem a bit unerealistic to me.

Thx

### RE: How to calculate battery life for specific application

cross posted at Thread248-105124

TTFN

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