Cheap external battery?

Apple iPhone - Cheap external battery?

Has anyone tried one of those cheap external batteries sold on eBay for 7 or 8 dollars with free shipping? Do they work at all?

iPhone battery
I wouldn't trust them - the only 'cheap' externals I am aware of are the ones that use Double AA batteries and are just a 'conversion' that take battery power from AA and send it over a 30 pin connector to the iPhone for a quick top off. You would be much better off investing in either a Mophie Battery Case or if you prefer one of the Power Blocks that allow you to charge via USB cable -

Power Blocks
http://www.mophie.com/category-s/53.htm
Reserve - $40
Boost - $60
Powerstation - $100

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What about those silicon cases with built in battery and solar panel in the back...seems to be the perfect solution your iphone always charged:

On ebay search for "iphone silicon solar"

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I've bought several from eBay or couple inexpensive online dealers for 8-10 each. Don't know what you are looking at but buy from someone with lots of good sales for the item you are looking at.

Ones I've gotten have filled a nearly empty phone once. So figure less than a full charge to be honest. If really working on a project, mail, just leave plugged in and work. Like of bulky and need to be careful, but have been pleased. If going to town put a couple of them in a carrier just in case needed. Wifi in town if often weak so sucks power. Just our experience.

Have used on an iPod, but iPad needs much more battery.