s high quality Dell WU946 battery will get your laptop up and running the right way at a reduced price. The battery dell WU946 has been precision-engineered and rigorously tested for capacity, voltage, compatibility and safety to exceed original equipment manufacturer specifications. The quality of this dell WU946 battery is certified as well by TUV, RoHS and the CE to name a few. It ships fast to you and we will stand behind our products for 1 full year. Li-ion batteries do not suffer from the memory effect. They generally last between 300-500 charge/discharge cycles.