why is my phone turning itself on and off when i put in the battery?

[AC Question]

my phone is a Samsung galaxy grand 2 duos and i purchased it in November 2014. Recently (even after i replaced the battery) it charges very fast but dies just as fast, i charge it to 100% 3 times a day on average.
today it switched itself off at 50% and refused to come on. when i removed the battery and replaced it it came on showed the make and model of the phone and then flashed to the logo before switching itself off again and repeating this process whenever i put the battery back into the phone over and over again until i pull the battery out.

 

[H3aTeRzz]

Hi

It would appear that your battery is defective. I WOULD NOT INSERT IT BACK IN. Try another battery. You can damage your phone with the constant power ups/downs.

Hope this helps!

CHris

 

[Rukbat]

Charge the battery in an external charger. I suspect that it's not really charging in the phone. (You'll definitely ruin the battery by running it discharged constantly, although some phones can handle the voltage changes from fully charged to 50% with no problem.)