on the type of phone.
This article explains more http://www.pcadvisor.co.uk/features/security/3319310/do-i-need-antivirus-software-for-my-smartphone/
You will see that a majority of threats comes form user installed apps, meaning that it is the user who installs malicious apps and so it is the user who allows malware into the phone.
As for AVG I am betting that it is running continuously in the background and so that is why the phone's battery does not last long between charges, so I would perhaps turn off the real-time scanner when the phone is not in use.
(Note reposted as my first post had too many errors).
My friend has a telephone with access to internet.He is running avg antivirus free edition and his battery keeps running low fast.Is that because he is running an antivirus program in real time?Does a telephone really need an antivirus program?Thanks