Amnergy&reg; Laptop / Notebook Battery Replacement for Fujitsu LifeBook AH531 Amnergy Brand Battery Is Designed Using the Best Cells and Latest Safety Features to Work as a Perfect Replacment for the Original Battery. Guaranteed to Meet or Exceed Original Specifications. Brand New, Protective Retail Packaging, Each Product is Sealed with Anti-Static Shield Sleeve. Lithium Ion (Li- ion) Battery, Rechargable with No Memory Effect. Premium Quality, 100% OEM Compatible.