I review gadgets every week, and I love it, but nothing makes me giddy like trying out a new solar charging system.
There's something about pulling electricity from the sun that makes me feel like I'm getting away with something - like I'm stealing electricity.
Of course, then I look at the price tag and realize I'm paying for it upfront, but if I use it enough, it will pay for itself.
The GoalZero Sherpa 50 Solar Recharging Kit is a larger sibling of the ultralight Guide 10 Plus kit I reviewed a few months ago.
The Guide 10 charger was about charging AA batteries and small gadgets such as smartphones.
The Sherpa 50 kit ($360) features larger solar panels and a battery big enough to power a laptop.
I think about using solar power to charge my gadgets in two ways - stationary and on the move.
The Sherpa 50 features a Nomad 13-watt solar panel, which by itself gathers more than enough energy from the sun to charge your smartphone or tablet.
That's great, but who wants to be away from his phone for a few hours while it's tethered to a solar panel? That's fine if it's your only option, but luckily these days we have other options, such as battery packs.
It's more efficient to use the solar panels to charge a battery pack and then use that battery pack to charge your gadgets or power them when the sun goes down.
The Nomad 13 can be set out in the sun to do its work if you're going to be returning to the same spot, but if you're hiking and sleeping in a different spot each night, you'll want to attach the panels to your backpack so it can charge the battery during the day.
If you're on the move, the panels won't be constantly facing bright sunlight, so the charging will take longer. Unless it's really overcast, though, the pack should be powered up by the time your day's hike is complete.
Folded for storage, the Nomad 13 Solar Panel measures 10.5 by 7 by 1 inch and weighs 1.6 pounds. You open the panel like a book to reveal the two letter-sized solar panels.
Behind the panels is a zippered mesh pocket that can hold your battery pack and cables.
That mesh pocket also holds the charging electronics, which include a USB port for direct charging, a 12-volt cable to charge a Sherpa 50 battery pack, a cable to charge a Guide 10 Plus battery pack and a cable to daisy-chain the Nomad 13 to GoalZero's other solar panels for increased power gathering.
The Sherpa 50 battery pack is powerful (50 watt-hours) without being too big.
Measuring 4.5 by 5 by 1.5 inches and weighing just more than a pound, the Sherpa 50 can charge a USB-powered device, any gadget with a 12-volt accessory plug (think the power outlet in your car) or a laptop.
Laptops are powered via a special higher-powered port or through an optional inverter ($49) that allows you to charge using your laptop's power cord.
A small LCD screen shows the remaining battery power, and a small LED light provides some illumination if you need it.
GoalZero says the Sherpa 50 can power a typical laptop for a little more than two hours on a full charge.
The Sherpa 50 can be charged up in three hours from an AC wall charger, three to four hours from a car's 12-volt power outlet or six to 12 hours from the Nomad 13 solar panel. In full sun, it will take closer to six hours; on cloudy days, it will take longer.
So how do they work?
I'm not a hiker, so my testing of the solar panels was in my backyard. You'll get better solar collecting if you tilt the panels toward the sun instead of just laying them flat on a table or the ground.
I found the charging estimates to be accurate. By the way, keep the battery under the panels when it's charging so it doesn't overheat.
I think the panels and battery are small and light enough to find a permanent spot in a serious hiker's backpack, or even in a drawer for use during a power outage.
If you don't plan on using the Sherpa 50 regularly, GoalZero recommends that you charge it to 50 percent power and remove the fuse for long-term storage.
It's a good feeling to know you've got a source of power when you need it.
GOALZERO SHERPA 50 SOLAR RECHARGING KIT:
-Pros: Small, light, powerful battery. Easy to set up.
-Bottom Line: Still kind of feels like stealing electricity - in a good way.
-On the Web: goalzero.com
Explore further: Panasonic releases a solar charger with USB, AA battery slots and LED lights