Amazon.com: PhotoHighQuality Photo 2X Batteries + Charger, Compatible for Olympus EVOLT E-30, Olympus E-300, Olympus E-330, Olympus E-500, Olympus E-510, Olympus E-520, Digital Camera : Electronics
2x Pack - Olympus E-520 Battery – Infinisia
Synergy Digital Camera Battery, Works with Olympus E520 Digital Camera, (li-ion, 7.4V, 1850 mAh) Ultra Hi-Capacity, Compatible with Olympus BLM-01 Battery - Walmart.com