1900mAh USB Rechargeable External Battery for iPhone 4 (White)

Pros: - Emergency energy for your iPhone!
- Works perfectly with my iPhone 3GS 32 Gb.
- Leds to indicate the charge level.
- White color for white iPhones!!!

Cons: - A little big (aprox 1/2 iPhone).
- Sometines, the leds that indicate the charge level don't work correctly.

Other: With this external battery, you can charge your iPhone a 40% aprox with full charged battery. It's perfect for travel and give you the security that you'll never be without battery in your iPhone.
¡¡¡¡¡A great deal from dealextreme!!!!!

Pros: Works great and came with approximately 50% charge (2 LEDs were lit up when I checked the battery life remaining). It also came with an iPhone cable, which was a surprise cos some of the reviews said it didn't come with any cable. Works great for charging my 3GS. You can also plug it in to charge your device and plug the battery to charge at the same time.

Cons: Plastic cover is quite bulky. Couldn't find anywhere to put the cover while it's in use. The iPhone cable that comes along with this is of lower quality than the original Apple cables. I didn't try to see if you can sync over it, but it charges the battery and my iPhone fine. I'd probably keep it just to charge the battery and use my original cable to charge my iPhone and for syncing.

Other: If you always face the problem of your iPhone running out of juice before the end of the day, this battery is perfect for extending your battery life.

Pros: It can charge my iphone 4 up to 65% which mean if you want your phone to reach 100%, you can go below 35% battery life. My friend bought one too. His can charge up to 70%. For backup 65% is good enough. Else you just buy 2 of them. Overall a good backup charger. Well a good charger so no cons to report. Recommended to buy as a backup. It is cheap and handy. Easy to carry

Cons: Well a good charger so no cons to report. Recommended to buy as a backup. It is cheap and handy. Easy to carry

Other: A good backup charger. Recommended to buy. So if you want 100% just buy 2 of them.

Pros: The price is very good and it really gave my iPhone 4S a good charge. It itself charges up quickly and you can it charge it and use it to charge your phone at the same time.

Cons: The weak point is the plug at the top which plugs into your iPhone. It is only supported by the 4 soldered wires and once it snaps, that's it.

Other: I've just ordered a different model from DX to try out but if I would buy another one I would carefully saw it open and pack the area round the top plug with epoxy resin to support it. If you buy one. glue it or be very careful and only use it in the lying down position. Alternatively don't lend it to your kids!