... over-charge, over-put, over-current. Built-in valve prevent the core form explosion, make sure the battery safe.More than 500 times the recharge ... ). All return shipping cost (Cost to ship the item back) will be the buyer’s responsibility. If you have any questions ... and parts, accessary for various mobile phones, mainly focus on the brand of Blackberry, Apple ( iphone,ipad , ipod), HTC, SAMSUNG ...