>>1694369A small one. No need to bring anymore. They are heavy and i sometimes don't even go through a full one. Though i have a $200 phone thats 4100mAh. Usually i'll be good not even bringing it.
If your phone goes from 100% to 0% in a full day of using it maybe a good idea to get a new one. Mine usually lasts 3 days with bluetooth, wifi and cellular network on. A week with aeorplane mode on.
I only bring one for emergency's though
