Cinch Power 5000 mAh External Battery for Blackberry 8520, 8530, 8900 Curve + Travel Adapter

It charges everything the adaptors fit. But, it is a must to keep it "DRY". You'll love it.

The box and your web site say "5000 mAh" battery pack. It is only in the fine print of the packaged document does it say "5000 mAh at 3.7V". So they are talking about the current capacity of just the internal battery.This means that the most I can get out of this power pack is 3700 mAh at 5V. Furthermore, given typical power conversion efficiencies, I will be luck to get 3000 mAh at 5V. That is a far cry from 5000. Why advertise a mAh rating that cannot be accessed? This is deceptive.Once I got past the deception, it really is a good 3000 mAh power pack. I particularly like that it power down when the load is removed and constantly shows me the state of the internal battery.Sometimes my iPod Touch indicates that the voltage from the power pack is out of spec low. When I wiggle the cable connections, the voltage comes back up. It is just a minor and rare annoyance. My guess is they didn't take into account the voltage drop in the cable. It only takes about 0.5 ohms of cable plus connector resistance to drop the voltage from 5.00V down to 4.75V (at 500 mA) which is the lower limit for a USB.

I got this external battery for my 3G iphone mostly for occasions such as small trips or waiting times. It is pretty easy to use and carry. It can last my iphone for at least a full day with frequent uses of different applications, such as mini games, internet browsing, or map directions. It's a good purchase!