Amazon.com: DR. BATTERY SB03XL Laptop Battery Compatible with HP EliteBook 820 G1 820 G2 720 725 825 G1 G2 717378-001 HSTNN-LB4T SB03046XL 716726-421 716726-1C1 HSTNN-IB4T [11.1V/4000mAh/45Wh] : Electronics
Synergy Digital Laptop Battery, Compatible with HP EliteBook 820 G1-G9T44EP Laptop, (Li-Pol, 11.1V, 4140mAh), Replacement for HP 716725-171, 716725-1C1, 716726-171, 716726-1C1 Battery - Walmart.com
Battery for Hp EliteBook 820 G1, 820 G2, 720 G1, 720 G2, 725 G1, 725 G2 Laptop. - Vision IT