2200mAh Rechargeable External Battery for iPhone 4/3GS (Black)

Pros: Cheap and affordable Easy to use Design looks nice and has this little blue/green lights when you pressed wants to check for the battery remaining.

Cons: None?

Other: Cheap and price worthy. If you buy similar product out on the street, would cost at least 1.5times more.

Pros: Great size, weight and super cheap to buy. Can be charged on a dock, or with a dock connector. Nice matt black finish makes it easy to hold and use. When connected to the iPhone4 it is snug and I could easily watch a movie with this battery attached. Nice colored LEDs tell you it's charge status, and how much power is left.

Cons: Can't be used with any case on your iphone.

Other: Great price, and great to have around for emergencies. But I have to buy a dock extender to use this with my bumper on.

Pros: - Great battery pack for my iPhone 4. It is working as expected.
- Good finishing, solid build. There are 2 ports, one for giving power to iPhone, and the other for charging itself from cable (not provided).
- Cheap, same functionality with other heavily promoted juice pack

Cons: - It does not work if your iPhone has case. You need to remove your case to plug this battery pack perfectly.
I think there's no cons in this case, I'll use it for couple months to see if it can sustain charge and discharge on daily basis.

Other: This is great bargain for those who seek iPhone juice pack. 2200 mAh is more than enough to charge an iPhone to full condition.

Pros: The battery is 2200mAh wich is very good because you can charge your iPhone or iPod completly. Also you can charge with the same iPhone usb cable, so there's no problem charging the battery. The battery has 4 led with a button to show you the battery percentage and i'ts very useful!

Cons: If you have an iPod, it is so much thiner than the external battery, but it's not a problem!

Other: Its very cheap and works fine. I would buy it without any doubts! It's A++!

Pros: The price is right, fit and finish are excellent. Does not look like a cheap booster attached to your iPhone.

Cons: Stopped working before I needed it on a trip.

Other: Can't beat the price, maybe I should buy two so I have one when I really need it. Two are still cheaper than any other decent options :-)

Pros: good. Can be deployed during emergency.
start charging at 10% battery life left - throughout the charge, constantly playing 3G games with it and the phone batt rose to 50%+ before the rechargeable battery went empty

Cons: battery is 2200mAh don't know if i got a lemon set or what, mine no matter how i charge it will show 4 bar of indicator but e moment i plugged it into my phone within 5mins it will becomes only 3 bar.

Other: good for anyone w/o casing. The casing will result the charge to not secure properly and stop charging

Pros: To me an external backup battery is a must. Using 3G drains the phone quite fast and sitting and waiting beside a wall outlet is not productive. When I see that I need a boost to the phone I just plug this in when I'm walking and now I can last a whole day without having to be stuck waiting for the phone to charge up enough use again.

Cons: This will not fit if you have any king of gel skin cover. I found it very annoying that I have to remove my gel skin to use it especially when it was so close to fitting. I got so annoyed that I modified the mount area by shaving it down to expose the plug another millimeter just to get it to work with the gel skin on.

Other: If you are always moving and using the iphone all the time this is great to have. It will save you time and knowing that you will not be caught with a dead phone is very stress relieving.

Pros: Good quality. Surface finish is OK. Lightweight. Both for 3Gs and 4. You can charge your phone two times with this unit. Can be charged by any USB.

Cons: No protective cover for connector, connector can get dirt in. Cannot be used with any bumper or cover. You should take off tyou protective bumper or case to fit this unit to your iPhone.

Other: Price/performance is OK. Just buy if you are away from wall outlet for long times like at a concert area, holiday etc.. I bought 2 units and very satisfied with them.

Pros: -Inexpensive
-Easy to use
-Powerfull (more than a full charge of my iPhone4)
-It's quite light

Cons: -built quality is a little bit light (you must be carefull when you plug it)
-iPhone + battery is quite long… so the phone isn't so easy to use while connected.

Other: It does what it's meant to: completely charge my iPhone4 and giving me a full day of intensive use. My wife uses one to charge her old iPhone 3G whose battery is (nearly) dead, it makes possible to use it a whole day long (but not too intensively).
I've recommended it to my friends…

Pros: Performs its functions at 100%! Very compact and slim that easy, toast does not require much space and you can put in your pocket or in your bag. The charge holds fine, iphone is charging too quickly! Very suitable for those situations when you are somewhere far from civilization, for example in a campaign or on vacation.

Cons: Absolutely no cons

Other: It's a great subject, I think in the near future I will book myself yet:)