Portable solar panel tests well, but it’s a heavy load in your bag.
The Solartab ($97 and available on
Amazon) combines a 5.5-watt solar panel with a 13,000 mAh battery into an iPad-sized, neatly designed all-in-one package that’s robust, attractive, and well thought out. It can recharge both from a micro-USB port (at 2 amps) and via the solar panel (peaking around 1.5 A in full, cloudless sunlight), and provides power through two USB Type-A connectors at up to 2.1 A per port.
Its trouble isn’t any of the above; everything tested just as expected. Rather, it’s that it’s too expensive and too heavy for the job for which it’s designed. The Solartab seems designed for people who will be away from any source of plug-in electrical power—car charger or AC—for days at a time.
But in nearly every circumstance I can envision, you can find a cheaper, lighter, or more flexible alternative by going solely with a higher-capacity USB battery pack, or combining two separate products from other manufacturers.
It has its day in the sun
The Solartab combines a very decent size of solar panel with what’s now a mid-range high-capacity battery. The package is nifty. It’s almost exactly the dimensions of an iPad Air and slightly thicker. It has a flexible, firm cover with a stretchable strap that doubles as a positioning stand to angle it towards the sun. The unit has a smooth aluminum finish, well-placed ports, and a lot of attention to design and build details. The Solartab weighs 2.6 pounds, and measures 9.5 x 7 x 0.75 inches.
But at 5.5 W, the solar cells can only recharge somewhere in the 1.5 A range (when converted to the internal batteries’ native voltage), and that only with full sunlight and the right angle, which changes through the day.
Because this is an integrated design, I couldn’t tease out the exact charging rate. So on an unseasonably cloudless, sunny, hot day in Seattle, I left the Solartab pointing south for about 10 hours as the sun tracked over the front yard. While I could have adjusted it several times, I didn’t think it’s reasonable to assume the target user will.
The Solartab has four green LEDs on the side that indicate charge level. However, the LEDs light up when the percentage is passed, rather than indicating a level. That is, they correspond to just above 0 percent, 25 percent, 50 percent, and 75 percent, rather than 25/50/75/100 percent. I drained the battery using a power sink as completely as I could, and after its stint in the sun, two green LEDs were lit when the button was pressed.
Using a USB power measurement device, I then drained it again and recorded about 3,500 mAh after converting units for its 3.6 V battery. That’s enough to charge an iPhone 6s fully about one and a half times, or bring an iPad Air from 0 to maybe 30 percent, buying several hours of continuous video playback, for instance.
With a little more effort in changing position, I could have eked out perhaps 10 to 30 percent more charge. And later in the year, it’s possible with perfect positioning and a cloudless day, I might have doubled the overall charge. (The company says in the right circumstances, the battery should recharge to its full capacity in 12 hours, or averaging a reasonable 1 A plus some change.)
Recharging from AC power is quite nice, as it supports 2 A over micro-USB and includes a high-amperage adapter, which is usually a separate purchase for battery packs. It took about two hours to cross 50 percent and about five hours to charge in full.
As I said at the outset, this is all fine and dandy. But once you compare its features to other options, its advantages seem to fade away.
In brightest day, in blackest night
Here’s my quandary with the Solartab in a nutshell: it doesn’t charge fast enough nor have enough capacity to be worth its weight and price. In any case I can imagine for needing a solar charger, a higher-capacity batter pack (or two) possible adding a higher-wattage charger make more sense.
If you’re packing in to a campground, on a multi-day hike, or driving to a cabin without any electricity, then the odds you’ll have the ability to leave a charger out and soaking in sun seem low for any extended period. Or, if you can, you probably want to carry the battery with you as a backup without the weight of the solar panel.
There’s also the issue of calculating how much power you might need if you’re away from electrical sources for several days. If you or your party keep cell phones on, and there’s a distant signal, the cell radio runs at full power and will suck the phones dry sometimes several times faster than in an urban area. If you want to be able to watch movies on an iPad at night, that’s a different use case, and might require solar recharging while off the grid.
However, in all the scenarios I envision the Solartab making sense, it’s not the best option. For half its $100 price tag, you can purchase the well-reviewed
Anker Astro E7 26800 mAh USB battery pack ($50 and available on
Amazon). It weighs 1.1 pounds, measures 6.5 by 3.1 by 0.8 inches, and stores twice as much juice. That’s enough to charge an iPad multiple times or re-energize several iPhones for a week or two.
If you need a longer charge, rather than fuss with solar charging during daylight hours, you could pack two Astro E7s to match the Solartab’s price and still be carrying less weight. (The E7 can recharge at up to 4 A with the right charger, so getting 30 minutes plugged in at a visitor center can jam a couple thousand mAh back in, too.)
For extended trips and a safety margin, or for higher battery use if you’re taking and editing photos and recharging a camera and an iPad, you might want solar. In that case, pairing the Astro E7 with Anker’s
PowerPort Solar Lite ($46 and available on
Amazon) seems like a better choice. It’s 11 x 6 x 0.75 inches folded and weighs about 12.5 ounces. It unfolds to 18 x 11 inches, and reviewers like its performance in partial sunlight. The charger should deliver at least twice as the Solartab in similar conditions.
There’s nothing wrong at all with the Solartab; it’s just not the right solution unless you’re absolutely certain you want the slimmest all-in-one design regardless of weight and cost relative to performance.