Compare Battery Deals

newegg offers the Griffin Powerjolt SE Car Charger for iPhone 5, model no. GC36547, for $29.99. This $20 mail-in rebate cuts it to $9.99. With free shipping, that's the lowest total price we could find by $10. Features include 10-watts total power and a lightning port. Rebate expires May 29.

Update: The price has dropped to $24.99 before rebate, $4.99 after.

Star-Doo via eBay still offers this 12,000mAh USB External Battery Pack in Blue (pictured) or Pink, model no. PB-A408, for $15.98 with free shipping. (Select each item to see this price.) That's tied with our mention from a week ago as the best price we've seen for any 12,000mAh portable battery charger. (Outside of the price below, it's also $24 under the best price we could find for a comparable battery pack elsewhere.) It comes with several adapters suitable for most types of charging ports, including iPhone, iPad, HTC, and other smartphones.

A close price: Campus111 via eBay has it for $14.38 plus $1.19 for shipping.

Pens N' More via eBay offers the Rayovac Platinum NiMH Rechargeable Battery 4-Pack in AA (pictured), model no. PL7154, or AAA, model no. PL7244, for $7.99 with free shipping ($2/battery). (TNT Deals via Amazon charges the same price for the AA with orders of $25 or more.) That's tied with our mention from three weeks ago as the lowest total price we could find for either pack by $1, although we saw these AA batteries for a buck less in August. These batteries can purportedly be charged up to 300 times.

Of note, add five 4-packs to your cart for an in-cart price of $31.95 with free shipping ($6.39/pack), yielding another price low.