One of the problems with having more than one portable gadget is that you're often obligated to carry around several chargers--not all devices have the same charger jack, after all. Some of us also have separate chargers just for the car. If you're not near an outlet of any kind, you either have to go without power or get one of those emergency alkaline battery chargers. All of those different chargers can add up to a lot to carry.
The Trans4m Multi Power Source, however, combines several charging methods into one portable unit. At first glance, it looks rather bulky, and is about the size of a large power brick. But there's a reason for its size--it houses up to four different charging options. You can plug it into an AC outlet, or a DC outlet in the car, hook it up to a 9V battery, or use two AA batteries. On the back of the Trans4m are two USB slots so you can charge two devices at once.
At the bottom of the device is the AC plug. It can be folded flat for storage, or flipped out when you want to use it. Trans4m includes an optional international adapter for use in another country. Also on the bottom are the connectors for the 9V battery. On the top of the Trans4m is where the AA battery compartment is housed. Simply flip up the plastic lid to access it. By default, the DC car charger is folded into the compartment for storage. You can swivel it out to plug it into your car's DC outlet. Also on the top of the device is an LED indicator that lights up when charging.
The Trans4m comes with three different USB cables--a Micro-USB cable, a Mini-USB cable, and a USB cable for the iPod or iPhone. You can of course use your own USB cables if you have them, but it's nice that Trans4m provides a few additional ones. Perhaps our only gripe is that it doesn't offer USB cables for the more obscure connections, like for Sony's PlayStation Portable or certain Nokia phones. Still, most devices use one of the three provided connectors, so we're OK with it.
We tested the Trans4m with a Verizon Wireless MiFi 2200 and an Apple iPhone 4. We were pleased that we could charge both devices with the same device. We found the plastic battery compartment lid to be a bit flimsy, and were afraid that we might snap it off. Also, when charging via the AA batteries, the car charger needs to be flipped out the whole time, which can be a little awkward. It appeared to charge the devices within the normal duration of a few hours, but we will do additional testing to be sure.
The Trans4m Multi Power Source is a handy all-in-one portable charger for most of today's modern gadgets. At only around $29.99 retail--you can find it for as low as $15 online--it's a great deal if you want to only carry one charger around.