Cellphone Battery, 1100mAh, Li-Ion
From Amazon
MicroBattery MBXNOK-BA0017 Replacement Mobile Phone Battery/Battery Black – Replacement Parts for Mobile Phones (Battery/Battery, Nokia, Black, Lithium-Ion (Li-Ion) 1100mAh, 3.7V)
Compadvance
COREPARTS Battery For Mobile 3.7Wh