As one of its daily deals, All4Cellular offers this Stitchway 1900mAh Backup Battery 3-Pack for Apple iPhone / iPod, model no. CHEX-ALL-BK-08-319, for $9.99 plus $2 for shipping. That's $4/battery and $6 under the lowest total price we could find for this quantity elsewhere. (For further comparison, we saw a single unit for $4.49 shipped three weeks ago.) It's compatible with the iPhone 4/4S and 4th generation iPod touch, as well as other models. Deal ends today.