My samsung galaxy note 4 restarts often

[saizcrzy]

My galaxy note 4 restarts often, works perfectly fine when connected to my charger. it restarts once i remove it from the charger. when reconnected to charging it shows 100% battery too. can anyone let me know how to fix it, should i change my battery? I wont get warranty at my home town.. coz i bought the phone from far east and currently using in india. I've been using the phone since february, and was perfectly fine. Kindly reply or suggest what i need to do.