I have a Iomega Prestige 2TB usb 3.0. It requires an outlet. I know that 2.5 external hd can draw power from the usb port, but the 3.5 like the one i have are required to be plugged in. I was wondering if there is a portbable battery that can be attached to it so that it can draw power from it. I know its not ideal and make the thing heavy, but I'm just wondering if a thing exsists and what it would be called. Think of an iphone with an iphone case charger. thats sort of the result i'm looking for.
It's not just power difference between 3.5" and 2.5". It is the voltage requirements. 2 1/2 In drives require just 5 Volts (reason thay can work off of a USB port AS long as the current does not exceed 0.5 Amps) However a 3.5" HDD requires both +12 V and +5 V. Normally +12 V is supplied from the "Brick" to the HDD enclosure then inside the Enclosure + 12 V goes to the drive and to a step down circuit that derives the needed +5 V.
If you are looking for portability (NO AC brick), you can get a recharable +12 V battery you could use that to power the HDD enclosure - BUT DO NOT recommend doing this as if the batteries dies while writing to the drive you could loose the drive.