Anker PowerPort 21W Review

The Anker 21 hit our review with some solid performance. This three-panel solar panel provides good power when you're off the grid and in the backcountry. While less portable than some of the other panels we reviewed, the Anker 21 gave a solid charge.

Performance Comparison

Direct Solar Charging Speed

One of the most important factors for a solar panel is how well it converts sunlight into energy. A panel's ability to quickly charge the devices you plug into it is a crucial metric. The 21W from Anker did a good job of charging an external battery at a decent clip. We placed the solar panel in the sun for an hour and it produced 1560 mAh, which was a decent metric for our panel.

In thirty minutes, the 21W from Anker charged a Pixel 3 from about 30%. This is impressive and on par with some of the larger capacity panels in this review.

Indirect Solar Charging Speed

The sun won't always be out when you're on a camping trip, out at base camp, or just looking for a charge from the sun. An equally important metric is how well a solar panel works when the sun isn't directly out. We tested the panels in full shade and partially shaded conditions and saw how much each panel put out.

In this category, the Anker 21W did fairly well. When left in the sun for thirty minutes, the panel charged our battery pack up to 10%. Then, after we shaded it and uncovered it some times, the panel reestablished a connection to the battery and resumed charging after about five minutes of attempting to do so. Most of the more significant models performed in this way, so our testing results were inconclusive as to which contender soared above all the rest regarding performance.

Multiple Device Charging Speed

The capacity to charge multiple devices at a time is a necessity for solar panels as often when one device loses charge, chances are that the other ones will as well. The 21W from Anker did an okay job at charging multiple devices. The battery charged the first port at 809 mAh and the second at 635 mAh, which was a bit below the rest of the devices.

Portability

The 21W weighs 16.4 oz which is lightweight, especially given its capabilities. Ounce for ounce, the panel is miles above the other 20W panels and even outdoes some of the panels of smaller capacities.

Folded, the panel breaks down to 11.13" x 6.13" x 1.13" while unfolded it is 26.25" x 11.13". For being a tri-fold panel with a large surface area of cells, the 21W is small and sleek. When folded, the width is about the size of a thin book or a magazine.

Should You Buy The Anker 21?

The Anker 21 is decently priced, especially when you consider its overall capacity. While you can find a panel with a much larger capacity for a similar or cheaper price, this panel does provide a good charge, it's well made and it comes from a reliable company, which adds to its value.

What Other Solar Chargers Should You Consider?

The Anker 21 is well made, light, and compact. It can also carry its weight as a charging powerhouse. It's okay when charging one or more devices, and can recover its charge even after being shaded for a few minutes. The panel also works decently well on overcast days, whereas some of the lower wattage panels could not keep a charge going when clouds were overhead. We are big fans of this long-time favorite, but the Anker 21 has finally come up against some fierce competition in recent years.

For better charging capabilities and better handling of multiple devices, try the Big Blue 28W, which comes at a slightly higher price. Another great options is the X-Dragon 20W SunPower which performs as well as the Anker 21 but at a little less of the cost.