Power Output
The EnerPlex Commandr 20 charges devices quickly and delivers excellent power output. In trials with our test smartphone, the Commandr 20 generated an average of 4.03 volts, and charged 1% of our test smartphone every 1 minute and 27 seconds — tying it for second place among all portable solar chargers reviewed. With an optional converter box, the Commandr 20 is also capable of powering both 12V and 19V devices.

Power/Size Ratio
EnerPlex’s Commandr 20 is a fairly large solar charger, with six 5.5” x 11” panels for a total surface area of over 363 square inches. While this larger size helps deliver excellent power output, the Commandr 20’s overall efficiency — power output and charging speed per square inch of panel — is quite low, with a Gear Institute power/size ratio score of only 1.91. Based on our repeated tests and calculations, the Commandr 20 requires over three times the panel size to deliver the same amount of power output and charging speeds as our top rated device, the Renogy 14w E-PLEX. It should be noted however that the E-PLEX is not capable of powering 12V and 19V devices, and that efficiency scores for the Commandr 20 were 50% greater than all competing chargers of similar size and capability.

Durability
Durability for the EnerPlex Commandr 20 is outstanding. Unlike most other chargers, the solar cells on the Commandr 20 are placed directly onto an extremely durable, synthetic canvas backing. This allows the panels and the entire charger to be flexible, lightweight, and extremely rugged. In our tests, the panels withstood impact strikes from a hammer of approximately 15 and 30 pounds force without any real damage or impairment. The panels and entire charger also withstood well beyond 180 degrees of twisting and torsion.

Features
The EnerPlex Commandr 20 is extremely versatile. With the addition of the EnerPlex Regulator Kit and adapters, the Commandr 20 is capable of accepting power input from multiple solar panels simultaneously, as well powering USB, 12V, 19V, and other devices.

Value
At $299, the EnerPlex Commandr 20 was easily the most expensive portable charger we tested, and was more than 7 times the price of the faster and considerably smaller Renogy 14w E-FLEX. That said, it has better durability and the ability to power 12V and 19V devices, features that the Renogy E-FLEX could not provide.