[Android Central Question]

It consumes battery at the rate of 3%/hour in any condition, either if its on stand-by or if turned off. what can be the cause? hardware or software?

[belodion]

It does so with the phone powered off, or with the screen switched off?
If the latter, and if you don’t use it at all - in other words, phone powered on but not actively used - what do your battery usage stats show as having used the charge?

[Rukbat]

If you turn the phone off with, say, 50% power, and turn it on 3 hours later and it has 41% power, the battery is shot and has to be replaced. Standby doesan't mean that the phone stops using power - the computer is still running, and it's running a lot of background apps (but 3%/hour would be a bit much - unless the battery is shot.)

If you keep discharging the battery as far as you can before recharging it, you can kill it in a month. Never allow a lithium battery (in phones or any other device) to discharge to less than 40% before charging it. If you can't charge it, turn it off. Lithium batteries are not deep discharge batteries.