battery power problem

What is the life of 9v Duracell alkaline and lithium battery?
The operating voltage is 5v and current is 500mA.

Just to point out, the operating voltage of your 9V battery is 9V, not 5V. What kind of device are you trying to power ?

There is competition with rechargeable batteries as new technologies producing higher capacities are being invented, so they are rated and marked.

As far as I can discover, battery manufacturers NEVER tell you the capacity of their ordinary batteries. I have searched their websites and all I get is stuff like, "7 times (or whatever) more powerful than ordinary batteries", which of course is no help to anyone, as they won't publish or tell you the capacity of their ordinary batteries.

I regard this a a great swindle, and I think it should be illegal to market batteries without marking their Ampere-hour capacity.

If you can find a battery manufacturer's site that give these figures, please let us all know ! Happy hunting !!!

Thanks for ur reply!
I am working on battery solutions for a microcontroller that works on 3.3V and has an RF chip.
I am looking for batteries that can last over 2 years for LP-WAN operations using 802.15.4
protocol.

from what I found online the capacity of a 9 volt battery if you draw 500 mA from it is just at about and hour.
so you are not going to get much life out of it in that application. it might last 2 years if it were disconnected and you just had the leakage current. Thats quite a bit of drain on the battery.

all the best

You need to measure or estimate your circuit load, factor in converter efficiency (if using one), and get an idea of your AHr load requirements and your battery discharge rate. Take that info and compare to battery specifications at a site like: http://www.panasonic.com/industrial/batteries-oem/oem/alkaline.aspx

You can then determine how many batteries of a given type you will need. You should also figure in shelf life and temperature effects for something expected to last a couple of years. I've never had a problem finding capacity specs or discharge curves from top battery manufacturers (Duracell, Panasonic, etc).

Depends of the battery capacity of course. Calculate the Wh of (Ah * 9V) the battery divide that by 2.5 that gives you approximately the time to operate. Roughly though.