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Wildtek Source 21W Review

Excels in charging efficiency, but fell short overall due to its size and weight
wildtek source 21w solar charger review
Credit: Wildtek
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Price:  $70 List
Manufacturer:   Wildtek
By Jane Jackson ⋅ Senior Review Editor  ⋅  Nov 11, 2019
  • Charging Speed - 30% 8.0
  • Charge Interruption Recovery - 20% 6.0
  • Multiple Device Charging Speed - 20% 4.0
  • Weight & Portability - 20% 5.0
  • Durability - 10% 7.0

Our Verdict

To narrow down our selection, we get nit-picky about things like weight, as some of these panels are similar in design and performance. The Wildtek 21 is a decent performer, but does not possess any features that are particularly outstanding or impressive. Its average performance in tests like charging speed and interruption recovery landed it in the middle of the road in this review. Paired with the fact that its weight is over a pound and a half, it's easy to say that we didn't reach for this panel first. While it's an adequate option, it lacks some of the key features that make up an award winner.
Fairly efficient
Reasonably priced
Lacks portability

Our Analysis and Test Results

While not our favorite panel of this season's new additions, the Wildtek 21W held its own in our performance comparisons. With reasonably high scores in charge interruption recovery tests and in charging speed, the Wildtek was up there among more expensive and larger capacity panels such as the BigBlue 28W.

Performance Comparison

Charge Interruption Recovery

In our charge interruption side-by-side comparisons, the Wildtek performed slightly better than the smaller watt panels but fell short of the high-performing, large capacity panels. The panels that have a built-in automatic re-start function, in general, scored higher in this metric than those that do not have this feature. For optimal charging, we suggest the BigBlue 28, as it was able to deliver a decent charge to our devices, even with intermittent shading.

wildtek source 21w solar charger review - here the wildtek and suntactics panels battle it out in the...
Here the Wildtek and Suntactics panels battle it out in the beautiful Wind River Range.
Credit: Jane Jackson

Charging Speed

The Wildtek 21 charged our 20,000mAh battery from 73% to 75% over the course of our 30-minute test period. This performance was similar to that of the RavPower 24W panel, though the Wildtek charged our iPhone slightly more (4%) over 30 minutes. In terms of efficiency, the Wildtek impressed us. Over 30 minutes, it charged our iPhone to 21%. Despite being outperformed by a few models, we were still impressed by the Wildtek's overall performance in this metric.

wildtek source 21w solar charger review - testing the wildtek with multiple devices plugged into its dual usb...
Testing the Wildtek with multiple devices plugged into its dual USB ports.
Credit: Jane Jackson

Multiple Device Charging Speed

Here, this panel's performance was more or less what we expected. Over the years, our testing has shown that even 20W panels have a difficult time delivering enough power to effectively charge two devices at once. The Wildtek is no different. This panel had a hard time making a dent in the percentage of our battery packs during our half-hour testing period.

wildtek source 21w solar charger review - the wildtek looks and performs very similarly to the other panels in...
The Wildtek looks and performs very similarly to the other panels in the 20 watt range.
Credit: Jane Jackson


Like most canvas, foldable panels in this review, the Wildtek fared well in the durability metric. The canvas showed no signs of abrasion, and the panels themselves performed well in slightly wet conditions. There were no signs of warping when the panel was left out for long periods, and we appreciated that it had a zippered pouch as opposed to a Velcro pocket design.

wildtek source 21w solar charger review - the wildtek has a larger storage pouch than most panels, complete...
The Wildtek has a larger storage pouch than most panels, complete with this internal elastic strap to hold cords in place.
Credit: Jane Jackson

Weight & Portability

The Wildtek 21 seemed exceptionally heavy when compared to the other panels in this review. However, it weighs in at 26.5 ounces, which is comparable to other panels that have three or four foldable sections.

wildtek source 21w solar charger review - another view of the large external storage pocket on the wildtek...
Another view of the large external storage pocket on the Wildtek Source 21.
Credit: Jane Jackson


The Wildtek 21 is less expensive than many panels of a similar size. Our Editors' Choice Award winner costs less and performs better than the Wildtek, making it a better option in terms of value.


The Wildtek offers average performance across the board. With nothing standing out to make this an incredible panel and no red flags or flaws, the Wildtek is a fine option for someone looking for a large-capacity panel for a reasonable price. It charged a single device relatively efficiently, while it struggled to charge multiple devices at once, like most panels of its size.

Jane Jackson
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