Batteries are supposed to be dull but a generation of power-hungry smartphones and tablets that struggle to get beyond a day on a single charge is modifying received wisdom. So far device makers have done their best to ignore the battery life issue and with the trend to fix batteries inside sealed cases there is no sign that things will improve in the short term; the underlying technology is slowly improving but only fast enough to keep up with larger memory sizes, higher processor speeds and better screens.

The solution is a portable rechargeable battery pack and the market is now booming with different designs and capacities. The buying proposition for these products centres around a few key statistics, starting with capacity. The more charge a battery can store (measured in mAh), the higher the cost and, generally speaking, the larger the unit. Some can also charge more than one device at a time.

As its name hints, Innergie’s PocketCell is aimed at users wanting a small battery pack capable of fully replenishing one or perhaps two devices on a single charge. It succeeds in this aim, weighing only 72g (2.5 ounces) in a small unit that can be slipped into a pocket quite easily. With some other products going to 6,000 or 7,000 mAh (including Innergie's own Pocketcell Duo), its 3,000mAh is at the lower end of the capacity range but the trade-off comes with its smaller size.

The unit is charged either by connecting it to a PC via the USB port (2.1 Amp) or to the mains, the adaptor for which is not supplied as standard. Ideally, it can be used with one of Innergie’s laptop travel adaptors such as the mCube Slim 95 reviewed by Techworld in May 2013. The connection to the smartphone or tablet happens through the Pocketcell’s clever 16cm ‘Trio’ cable, which incorporates a micro USB connector, Apple 30-pin USB and Mini USB in a single system.  Four LEDs indicate charge level with transfer to the target device started by pressing a recessed button.

We found Innergie’s claim that it could be charged in an hour about right with device charging happening reasonably smartly too thanks to the 2.1 Amp rating. Innergie makes a number of claims for the level of battery life it can supply, but this will vary by device. We found it good enough to fully charge a Google Nexus 4 and Sony Experia with a little to spare. It could also cope with smaller tablets such as the Nexus 7 but larger devices such as the iPad (which we didn’t test) would offer more of a challenge.

OUR VERDICT

The PocketCell might not sound particularly cheap at around £50 in the UK (or $59.99 in the US) but this is line with most of its rivals not to mention the price of devices such as smartphones and tablets themselves. Some will want a higher capacity but this adds weight, bulk and extra cost. The only other disadvantage is that lacking a mains adaptor it needs to be used either with a laptop or conjunction with one of Innergie’s other travelling adaptors. In an age of pathetic smartphone battery life it is starting to look as if external battery packs are becoming a necessary accessory for many consumers. With its good build quality, simple operation and reliable performance, this is an excellent contender for anyone looking to keep their device alive for longer.