Guaranteed 100% Original Battery Li3827T44P6h726040 For ZTE Nubia Z11 Mini NX529J - with a unique 45 days replacement warranty for manufacturing defects. All our products are thoroughly tested but you might run into some unforeseen problems if you do not use an expert technician. So, we strongly recommend servicing under expert technical supervision. Self-installation without required skills can be dangerous to the screen/device. Do not remove screen guard or warranty sticker until you are completely satisfied. Screen guard removal means acceptance of the product. New Lithium Ion batteries must be fully charged and fully discharged 2 to 3 times, before being fully conditioned. Please remember that a new Lithium-Ion battery's full performance and longevity is only achieved after 2 to 3 complete charge and discharge cycles. After you go through 2 to 3 cycles, you will never have to condition your battery again!