Portable solar power sure has come a long way in the last couple of years, and because we all seem to be a bit gadget-happy, it's a welcome trend that a number of small but powerful solar charging devices are now reaching the consumer market.
Many of today's high-tech smartphones, digital cameras, tablets, and e-readers have one big weakness, and that's their big appetite for power, which can rapidly sap batteries and leave users with a dead device until they can reach a power outlet and charger. When traveling or out away from the grid, that can be a big problem, but a backup power source and solar charger can come to the rescue.
I recently took a closer look at one option, the SunVolt, which is a great unit, but a bit large and heavy for packing in small spaces or long trips. A better lightweight option for a truly packable portable solar charging solution is the GoalZero Guide 10 Plus Adventure Kit, which I have spent the last few weeks putting through its paces.The Adventure Kit, which is comprised of a Nomad 7 solar panel and a Guide 10 Plus battery pack, offers quick charging of AA and AAA batteries, smartphones, and other gadgets, all in a very small package. The entire unit packs down to 6" by 9", and only measures about one inch in thickness (though the panel itself, except for the small charging junction and removable battery pack, is only about half of that thickness).
When unfolded, which is as simple as opening a single Velcro flap, the Nomad 7 presents two lightweight solar panels to the sun, and measures about 15 inches long. 10 loops are sewn around the edges for easy hanging or strapping down to a pack, and a zippered pocket on the rear holds the battery pack and any cables or accessories.
The monocrystalline solar panels in the Nomad 7 are rated at 7 W, and feature outputs for USB, a 12V port (for use with auto lighter adapter), and a port for charging the Guide 10 battery pack. According to the specs, the unit puts out 5V, 0.5A max (2.5W) for the USB port, 13-15V, 0.2A max (3W) for the 12V port, and the charging port for the Guide 10 is rated at 6-6.5V, 1.0A max (6W).
The Guide 10 Plus battery pack is a versatile piece of gear, as not only can it be used as a single unit for holding a charge (as a backup unit), but because it accepts both AA and AAA batteries, it can be used as a battery charger for your other rechargeable batteries. It comes with 4 AA NiMh cells (10Wh capacity), and when connected to the Nomad 7, will take a full charge in two to four hours. The unit can also be charged from house current via a mini USB connection.
On the Guide 10, the USB port allows for charging other devices, and is rated at 5.0V, 1.0A max (5W). The unit can charge a smartphone in a couple of hours (depending on state of the phone's battery and the power level in the unit), and because of its small size (2.5" x 4" x .75"), is a great little backup to carry with you. At the top of the unit, a thin cable loop allows the Guide 10 Plus to be securely fastened or hung while in use or being charged.
Two other features stand out on the Guide 10 to me, and one is that it has a power switch for turning the USB output on and off, and the other is the 100mW white LED light built into the end, which means that it can also be used as a flashlight (with a potential 100 hours of light on a single charge).
The Adventure kit is well suited to keeping portable gadgets powered up, with the Nomad 7 charging up the battery pack in just a few hours, and the Guide 10 Plus being able to fully charge a smartphone twice on one charge. For tablets and e-readers, the kit isn't capable of giving them a full charge, but it can add 25 to 50% to their battery life, which should be enough to last you until you reach a wall outlet.
Because the kit weighs in at just over a pound and has a small footprint, it can fit just about anywhere a book or article of clothing would, making it a great choice for lightweight travel. The Nomad 7 is weatherproof (and the panels are protected when folded up), and the construction on both pieces of the kit is rugged enough to stand up to daily outdoor use.
I found the Adventure Kit to be not only simple and efficient to use, but well designed and incredibly small and portable. It's been keeping my iPhone charged with solar power for the last couple of weeks, and I use it in two different ways. If it's daytime and my phone battery is getting low, I charge it directly from the unit while the panels are outside in the sun (the phone stays out of the sun in the rear zippered pocket). If my phone doesn't need a charge, I set the panel out in the sun and top off the Guide 10 battery pack during the day, and use the battery pack to charge my phone at night. Both methods are easy and quick, although if I needed to have access to the phone while it's charging during the day, I would need to go and sit next to it.
The GoalZero Guide 10 Plus Adventure Kit is listed at $119 (USD), and the Nomad 7 ($79) and Guide 10 Plus battery pack ($39) are also available separately. GoalZero also has a full line of other portable solar power solutions, such as the Nomad 13 solar panel (13 W output) the Switch 8 kit (3.5 W panel and battery pack).
[GoalZero supplied a review unit, but all opinions in this review are mine.]