Get Smart about Energy™


How much a portable solar charger weighs, its size, and its effectiveness are three important considerations when buying one of these devices. This is especially true for people looking for the best solar chargers for backpacking.

Backpackers and hikers don’t want to lug around a heavy or bulky solar charger. Yet, there currently exists no common unit of measurement that will help you compare the weight, size, and output of these products.

This article will introduce the concept of a new common unit of measurement called Sun Juice. Knowing a product’s Sun Juice will help you choose the right lightweight and powerful portable solar charger for your needs and your pocket. There are three factors that must go into the calculation of a unit of Sun Juice.

Sun Juice PlusFirst: The weight of the mobile solar charger?
Second: The bulk/size of the portable USB solar charger?
Third: The power output, or the number of watts that it generates?

Any backpacker or hiker who has carried around a heavy portable solar charger understands the importance of having a lightweight device. The lighter your pack, the less chance your muscles will hurt at the end of the day. And the greater the chance you’ll meet your daily hiking goals.

Weight is also important to anyone who cares about emergency preparedness. After a natural disaster, for example, you can easily and quickly grab a lightweight solar charger and get out of harm’s way.

Size is important, too. You can affix a thin, flexible unit on to your backpack. That way, your USB-powered devices can charge while you’re hiking. A thin charger that can be rolled up is also much easier to fit into your pack.

Power is the third factor involved in creating a unit of Sun Juice. How long does the portable solar charger take to power up your devices? Is it fast enough? You want your phone, Kindle, or other USB-chargeable device to juice up quickly. If you can find a portable solar charger that meets all three of these qualifications it would have a high Sun Juice rating. You would gladly pay more for a charger that earns a higher Sun Juice rating because it’s more effective.

It deserves a premium price because it’s easier to use than ones that have a lower Sun Juice rating. A product with a higher rating is lighter to carry. It slips easily into your backpack. It powers up your devices quickly.

Conclusion: The bottom line? There is a real need for a common unit of measurement that includes all three important considerations when buying a portable solar charger: 1) Weight, 2) Size, and 3) Power.

We propose that this unit of measurement be called a "Sun Juice".

Products that have a higher Sun Juice rating should go for a premium. They are the gold standard of portable solar chargers and should be recognized as such. For example, one product that would have a high Sun Juice rating is the SunJuice™, a lightweight, efficient, and thin portable solar charger. Its Sun Juice rating would be calculated using its weight (3.9 ounces), its size (.75 millimeters thick, 14 inches height, and 10 inches width), and its power output (7.5 watts).

Creating a common unit of measurement will make it much easier for backpackers and emergency preparedness “preppers" to find the right solar charger for their needs. This proposal to measure the efficiency of a portable solar device is a much needed addition to the portable solar industry.

At last consumers can evaluate portable solar products at-a-glance to quickly know which is right for them.