We always seem to be carrying more and more technology with us no matter where we go. So it's important to keep all your devices charged, even when you're far off the beaten path. We put the top portable solar chargers through head-to-head testing to find out which ones are the most efficient in direct and indirect light, which are the most portable, and which panels offer the greatest functionality.
Direct Solar Charging Speed
We set up every solar panel in the same open area with full sun exposure to test their direct solar charging speed. Every solar panel was hooked up to its own identical battery and left in the sun for one hour. Then, we discharged every battery, measured the mAh of charge with a digital multimeter, and recorded the results. We also hooked up the multimeter directly to the output of each panel to measure their output at peak sunlight efficiency. We recorded our results and compared them with the manufacturer's claimed output.
Indirect Solar Charging Speed
To measure indirect solar charging speed, we repeated the direct solar charging speed test with a large white sheet suspended above the solar panels in order to simulate a cloudy day. With this simulated cloud cover in place, we hooked up every solar panel to its own battery and left it to charge for one hour to see how much energy it could convert during that time.
Portability
To test portability, we measured the weight and dimensions of every solar panel. We measured them when folded and set up. We also carried them around and packed them in our backpacks and on our bikes. We set up every panel countless times to evaluate their functional portability.
Functionality
To test functionality, we assessed the features that make it more or less easy to use. We assessed how many devices each panel could charge, whether it had features to angle the panel towards the sun, if it came with all necessary cables, and other relevant aspects that contribute to functionality.
