Cellphones of the past came equipped with rechargeable nickel-based batteries with (Ni-Cd and NiMH). In the past few years, however, most rechargeable batteries used in phones are Lithium-based.
I’ve tested and reviewed EBL AA 2800mAh & AAA 1100mAh NiMH batteries and was very impressed. I often use them in my camera flashguns, flashlights, gaming console controllers and other gadgets ...