Running out of battery on your smartphone or tablet can be a real nightmare. It's made especially worse when you are out of proximity of a wall outlet. Here's a product that prevents this from happening.

The TYLT Energi is a little different to other portable battery packs we have reviewed in the past. The main difference is that this has a built in two pin American plug, which neatly flips out and into the body. Now the fact that you can charge the Energi over USB or via your computer and so on via a wall outlet gives this a real advantage over other options on the market. The ease of being able to plug it into the wall at night alongside my iPad and iPhone is convenient.

TYLT have crafted a compact and ultra light battery pack here too, which neatly fits into a pocket. The design is sleek, with the use of glossy black plastic over the entire exterior body and a single rounded edge at the top gives the battery pack a streamlined effect. The top houses a button which displays the amount of charge left and next to that sits an understated embedded TYLT logo. The build is also notably rugged.

The left hand side contains a flip out flexible Micro-USB cable and the front sits a USB 2.0 input. I tend to make more use of the front USB 2.0 input but the need for both is necessary. Also suppied in the box is a USB 2.0 to Micro-USB cable for charging only. TYLT claim charging to happen rapidly and I don't disagree, charge time appears no different here to what I've experienced charging straight from a wall outlet. Two devices can simultaneously be charged also, additional abilities such as these can always come in very handy.

The internal 1,800mAh lithium-ion battery provides a five hours of additional talk time claimed on the box. Charging a totally drained iPhone 5 with a fully charged TYLT Energi until it drained itself, took the iPhone's battery to 90% capacity, translatng to around six-nine hours of usage. It charged our iPad 2 battery from drained to 35%. This simply isn't enough juice as I would like, granted it's enough for those occasions when your stranded with a fully drained battery and just need to quickly use your device but for a serious extra days worth of usage, it's not anywhere near enough. The TYLT PowerPlant is more able for that task and that retails for only $20 more at $69.99.

Overall the TYLT Energi Portable Battery pack offers a nice innovative addition with the flip out wall plug to charge the unit and also seemingly charges devices at near the same speed as a conventional wall outlet. But the lack of capacity stored is a kick in teeth.