Power Output
The ChoeTech Foldable 19w delivers excellent power output and charged devices faster than nearly every other competitor.  In trials with our test smartphone the ChoeTech generated an average of 4.01 volts, and charged 1% of our test smartphone every 1 minute and 25 seconds — enough for second place, and a mere 9 seconds behind the fastest portable solar charger, the Renogy 14w E-FLEX.  The ChoeTech’s higher wattage rating, however, may make it a more suitable purchase for readers needing to charge devices with higher power requirements.

Power/Size Ratio
The ChoeTech Foldable 19w was actually the second smallest portable solar charger we tested, with a 138.75 square inches of solar cells divided into three 5” x 9.25” solar panels.  Earning a Gear Institute power/size ratio score of 5.07, the ChoeTech nearly tied with the Renogy E-FLEX for first place in power per square inch, and bested its next closest competitor by nearly 20%.

Durability
The ChoeTech Foldable’s panels are built from a polymer substrate and held together with a rugged synthetic canvas.  Overall durability is quite good:  the canvas case is extremely durable, and the panels themselves withstood impact strikes from a hammer of approximately 15 and 30 pounds force with only cosmetic damage, and without serious impairment.  The panels can also withstand a considerable amount of torsion, but appear to stress beyond approximately 90 degrees of twisting.  Though the ChoeTech’s overall durability is excellent, it is still however only average when compared to competitors.  

Features
Like many competitors, the ChoeTech Foldable 19w is a no-frills portable solar charger, offering two 2.5A USB charging ports, a micro USB charging cable, and an integrated velcro pouch for small storage.

Value
Priced at only $49.99, the ChoeTech Foldable 19w was among the least expensive solar chargers tested and nearly tied for first place in terms of power delivered per dollar spent.  In short:  the ChoeTech Foldable 19w is an excellent value and an outstanding buy.