I just bought the Xiaomi Redmi 3 [1] with 4100mAh. The battery life is excellent. 2 to 3 days of battery is a comfort I missed from the "dumbphone era".
1: http://www.kimovil.com/en/where-to-buy-xiaomi-redmi-3s-3gb-3...
1: http://www.kimovil.com/en/where-to-buy-xiaomi-redmi-3s-3gb-3...
Now if you want 2 weeks of battery life on a pocket supercomputer, well, good luck with that.