2x Pack - UpStart Battery Canon NB-4L Battery - Replacement for Canon NB-4L Digital Camera Battery (890mAh, 3.7V, Lithium-Ion) - Walmart.com
Amazon.com : Kastar Battery (2-Pack) and Charger Kit for Canon NB-4L, CB-2LV work with Canon PowerShot SD40, SD30, SD200, SD300, SD400, SD430, SD450, SD600, SD630, SD750, SD780 IS, SD940 IS, SD960 IS,