Has your mobile phone's battery been losing charge? The Xiaomi Original 2050mAh (Bulk), BM41 can be used as a spare power supply. It is designed for Xiaomi phones, more specifically the Redmi 1S models. The Lithium-ion (Li-ion) battery provides a capacity of 2050mAh to allow longer run time. To keep this mobile phone battery running at its full capacity, you should read and follow the manual on proper battery charging.