How long should 3200 mah battery last?

[Aserar]

Hi all..

I'm new to Android phone, and my first android device is a 5.9" screen phablet with a 3200mAh battery. Device is brand new, and I'm not sure if this is normal or my battery is defective, but if the battery is %100 (was unplugged right away) and I use the device for web browsing and light gameplay, with in one hour the battery goes to %80, even though I keep brightness at %0, no apps in the background, everything else is off (GPS, Cell data, Bluetooth, etc).

Is this normal? I'm asking because my 7" tablet last way longer.
if it is possible to give me an idea on how your batteries last in which conditions.
Thanks in advance.

 

[Bhushan Bharath]

Go to Settings>Developer options>scroll down to apps section and touch the limit background processes and set it to no background processes

 

[iOSConvert2k14]

Go to Settings>Developer options>scroll down to apps section and touch the limit background processes and set it to no background processes

I am also new to Android. In doing this, do it slow down the phone in any way?