Amazon.com: Synergy Digital Equipment Battery, Works with Graphtec B-517 Equipment, (Li-Ion, 7.4V, 2200 mAh) Ultra High Capacity, Compatible with Graphtec B-517 Battery : Health & Household
3 Pin Round Battery Charger Port with Red Connector #CNX-517
24v, 12-125-17, CAT NRR35 , XtraPower Batteries,
Battery for Graphtec B-517 GL220 GL200A GL450 GL500A GL800E GL820E Data Logger - Walmart.com