Based on this product's specifications, here are some alternatives and similar models
Battery Green Cell HP184 for HP ProBook 640 G2 / 645 G2 / 650 G2 / 650 G3 / 655 G2 — 11.4V 3400mAh LiPo, 6 cells, black
Summary description:
Replacement laptop battery Green Cell HP184 compatible with HP ProBook 640 G2, 645 G2, 650 G2, 650 G3 and 655 G2. Lithium Polymer (LiPo) pack with 11.4 V voltage, 3400 mAh capacity and 6 cells. Black, sold as 1 piece. Suitable for restoring mobile power, extending run time for work, study or travel and replacing worn original batteries.