Why is my Phone Powering off within 1 to 3 minutes even though battery full charged?

[1st Mobile Device]

Why is my Phone Powering off within 1 to 3 minutes even though battery full charged?
Was told due to downloading Google + and google + had a update few days later and it starting shutting down a lot of Verizon's programs. Had Tech support fix all these issues I think.. went to settings had phone change auto update to manual then // shut down several programs with force stop, clear data then restarted programs then uninstalled updates for google + powered off and restarted no phone does not start shutting down programs that control verizon so I know this worked but still will shut down after 2 or 4 minutes now.... Could it be the battery??? should i buy a replacement???
Model SCH-I535 Verizon White Samsung Galaxy S3

 

[Rukbat]

When you turn it back on, after it turns off, look at the battery graph in Settings. Press the graph and you'll get a second graph. In that graph, is the battery going down to 0 in just about 0 time? If so (and I suspect it is), it's a defective battery. Since it's a new phone, I'd ask for a free battery replacement. Badly misusing the battery should take more than 6 months to put it into that bad a condition. (It's actually a problem with lithium batteries that no one's been able to come up with a solution for yet - if you search lithium battery dendrite you'll find a lot of information about it, It can occur with a brand new battery through no fault of anyone's, so it's actually a manufacturing defect.)

If it's not under warranty, an S3 battery is about $10 on Amazon. Anker and Hyperion batteries are pretty good.