A-Solar are pushing the envelope with regard to solar technology. They're shrinking their charging solutions on a rapid basis. We were extremely impressed with the A-Solar Xtorm Lava Charger and couldn't quite believe that something of its size could charge devices so rapidly from just using the energy of the sun. But A-Solar have decided to squeeze their solar technology down even further and the finished product is called the A-Solar Xtorm Yu Solar Charger (model number AM115).

Design & Durability

The Yu Charger has an outer body constructed from grey silicone, making it resistant to water and general outdoors conditions. Useful for when you want to place the Yu in the sunlight on a damp surface, and it's worth mentioning that dirt and other debris are easy to wipe off the silicone. Its remarkably thin and ultra light 78g body may fool some into thinking it's flimsy and delicate, but its overall build is actually particularly solid and will hold up well from being loose in a bag or even kept within a pocket and abused from heavy impacts. The edges of the Yu Charger have excess silicone which act as a sort of bumper, giving greater overall ruggedness and make it easy to hold. Another initial concern we had with regard to damage was that the entire front solar panel is totally exposed, but we've not experienced any cracks or other damage to the panel even though we kept the A-Solar Yu loose next to heavy objects within the Rickshaw iPad Messenger Bag and commuted with the bag on a regular basis. We also left the Yu freely exposed to the sunlight as we travelled by using the included carbine hook and connecting the Yu Charger to the outside of the Booq Python Pack Bag.

Battery Display & USB Ports

A test button is fixed to the back of the unit and will display up to four white LED lights, reflecting the charge of the internal battery. A green LED to the left of these emits when the battery is charging, the brighter the light, the faster the charge. One female USB 2.0 output charging port and one micro female USB input port for charging the internal battery are built along the bottom edge of the Yu and silicone flaps cover and protect them when not in use. The USB 2.0 charging port has a maximum charge rate of 5V/1A. The iPad will charge with 5V/1A chargers (1.1A to be specific which 5V/1A is usually rated for) as the base rate, but in this scenario the amperage must be a tad below the required base rate, so its charge isn't strong enough to charge an iPad.

Battery Capacity

The Yu Charger has an internal battery pack which holds a maximum of 2000mAh. To put this into perspective it will charge an iPhone 5S and all previous models to maximum charge from drained. This is a nice reliable reserve that tailors itself more for charging a smartphone category device than it does a tablet, because these have higher capacity batteries and this in turn usually leads to a higher amp requirement which the Yu charger is unable to meet.

Solar Panel & Charging

We liked to keep the battery topped up whenever we could using the sun as our free energy source, but what we came to notice from having the solar panel exposed at near all times was that it would charge unintentionally from just sitting on our desk with exposure to both sunlight coming in via the windows and indoor lighting. You can also charge the Yu via the mains electricity if you so want to via micro USB (cable included). However, with a high enough energy transfer rate, when the Yu has no reserve battery left, it will charge a device such as an iPhone, a portable speaker like the X-mini Uno Speaker or a portable projector like the Microvision ShowWX+Projector straight from the sun. The time it requires to charge a device like an iPhone 5S or the internal battery straight from the sun on a zero cloud day, with temperatures of around 25-30+ degrees Celsius, takes roughly six/seven hours. Cloudy days, with temperatures of around 15 degrees Celsius, and even indoor lighting will allow the A-Solar Xtorm Yu charger to create electricity but at a slower rate.

In comparison to the A-Solar Xtorm Lava Charger, which has two solar panels that sport a combined peak range of 3.5 watts draw from its panels and could charge an iPhone 5S in around three hours with the temperatures and condition mentioned above, the Yu has a peak of 1.5 watts. It's not that surprising, the Yu only has one solar panel, but regardless of this its solo solar panel performed confidently throughout our tests. The panel is of a high spec, but the end result of less solar panels is a lower peak watt rate and therefore slower charges.

Overall

To really sum up the A-Solar Xtorm Yu Charger, it fits someone's lifestyle as more of a quick battery pack reserve which can be conveniently charged via the sun and indoor light, rather than a backup energy solution direct from solar technology that could be relied upon to charge a plethora of gadgets when engaging in activities such as camping or hiking. We feel that for these sorts of activities the A-Solar Lava Charger is better suited because of its greater capabilities. The price of the Yu charger is around half of that of the Lava, retailing at present for £49. This to us seems like a very fair price for such a rugged build and compact travel friendly design.