A-Solar offer a series of products under the XTORM banner, which comprise of a line of portable battery packs. This market is fierce with choice and the product we have, the AL-360 Power Bank 11.000mAh, is aimed at the high end. In fact, it's the highest specked battery pack in the XTORM series. 

The exterior is very Apple-like in design terms. Coated in white glossy plastic with a silver trim running around the middle, simulating aluminium. The style is very admirable and doesn't look out of place if you need to obtain some extra juice from it in public. In size terms, it's a little longer and taller than its competitors but that's justified from the amount of energy stored within it. It's also rather heavy, weighing just under 300g.

Two USB ports sit along the front, the right port slightly better than the left for charging purposes because it has a higher amp allowance. This can't be taken advantage of by all devices but the iPod touch, iPhone and iPad make use of it. The left port is recommended for general smartphones, tablets and other USB devices that can charge through USB. We can verify that the right USB charges exceedingly quicker than the left, when charging the iPhone 5 and iPad. It's identical to charging via a wall outlet. Usually battery packs only have one generic speed output. 

So how much charge does the XTORM AL-360 Power Bank hold? In iPhone 5 charging terms it can fully charge the device four and half times. This is very impressive and many devices, such as portable audio players, will only sip the reserves of the battery pack when compared to the iPhone. Not to mention that you can charge another device, say a Google Nexus 7, alongside an iPhone 5 simultaneously. The claim on the box is up to 50 hours of operating time, and from our tests it's very close, the combined iPhone charges delivered around 38 hours of usage. This is an ideal sort of solution to take with you for a weekend of camping. You could charge your tablet, phone and other devices and probably still have some juice left over.

We've been using this charging solution for three months. It's held a solid charge over this period and we only charged it via the included wall outlet during the night, so we don't know the exact period of time it takes to gain a full charge but it's definitely less than six hours. To obtain a reading of the charge level simply press the one and only silver button sitting on top. A reading in the form of green bars will appear, four bars is the highest level of charge.

In the box a carry pouch is supplied which is nice and useful. But our favourite added inclusion is the multi-USB cable. A-solar have included a USB cable that can be plugged into the Power Bank which allows for interchangeable tips. Several tips are included in the box with, Samsung Tab, Samsung Generic, Sony Ericsson, Mini USB and Micro USB. This opens the Power Bank up to a huge array of compatible devices.

The XTORM AL-360 Power Bank 11.000Ah is priced at €99/ £75, firmly sitting it within the higher end of the market. But it's one of the best options we've tested, with ultra fast charging and a whopping degree of stored charge.