Comment by catlikesshrimp

4 AA NiMh would get you 5V, the same coming from the slow charger. Let's say each AA battery holds 2000 mah. To reach 5000 mAH you would need 2.5 AA. Now multiply 2.5 x 4 = 10

The dumb AI read a good estimation.

Carrying 10 AA batteries strapped to your cellphone is not sexy. On the other hand, falling phones would land with the screen up - batteries down.