Sun King Pro Solar LED Lamp Is a Handy Portable Light and Backup Battery (Review)

Greenlight Planet Sun King Pro Solar LED light

Looking for a solar-powered light for a tiny house or camping trip? This model is a great little rugged and affordable option.

Most of the solar gadgets I've reviewed here on TreeHugger are primarily designed as charging units for mobile devices, which can be pretty handy for getting powered up on the go. But even when paired with a battery pack, they tend to be kind of one-trick ponies, no matter how many devices they can be connected to. One exception to that has been the WakaWaka light, which I really liked, as it does double duty as both a light and a solar charger, and can be used as a backup battery for charging devices after the sun goes down. The Sun King Pro, which I recently got to spend some time using, is another exception to that rule, and an exceptional device at that, as it does everything it claims to, and at an affordable price.

The Sun King Pro, from Greenlight Planet, is a bright LED light with an integrated 2800 mAh Lithium Ferro-Phosphate (LFP) battery and a separate 2.7W solar panel. The LED light and battery is housed in a rugged and water-resistant polycarbonate and ABS enclosure, and features three brightness settings (17, 50, and 100 lumens) as well as a USB charging port for connecting mobile devices for charging. The unit has an integrated webbing strap on top of it for use as a handheld light, and includes a removable steel stand that allows the light to swivel through 360 degrees and be positioned exactly where you need it, or can be used for hanging the lamp.

According to Greenlight Planet, the LFP battery in the unit is rated for up to five years of battery life, which is longer than many other common rechargeable batteries, and can power the LED lamp for up to 45 hours on a single charge (on the low setting). With a single full day's charge, the Sun King Pro is said to be able to charge a "typical mobile phone" and still have enough juice in it to provide up to 22 hours on the low setting, which I found to be plenty bright enough to do most tasks after dark. Dual indicators on the top of the unit give the user feedback on the state of the unit, with one displaying the remaining battery power when in use (on a scale of 1 to 5), and the other displaying the intensity of the charge (also on a scale of 1 to 5) when connected to the solar panel, which allows you to position the panel at the optimal angle for the shortest charge times.

"Slow solar charging due to improper panel placement can cause consumer dissatisfaction. With Sun KingTM, this confusion is a thing of the past. The intuitive solar meter continuously displays the solar charging strength on a scale of 1 to 5 using bright green LEDs. Everyone can now master solar panel placement and get the full satisfaction that they paid for."

When using this solar-powered LED light, I was really happy with both the quality of the light (diffuse and warm, rather than the ultra-bright concentrated light of other portable LED lights I've used), as well as the charging times (a single sunny day will deliver a full charge to the internal battery). The lamp unit is light and durable, and the solar panel, which seems to weigh more than the lamp, also appears to be durably built, and the whole package is pretty much dummy-proof. Simply connect the solar panel to the lamp, position the panel so that it's perpendicular to the sun, and let it do its thing (although you certainly can adjust the angle of the panel throughout the day to keep it pointed toward the sun). I think this could be a great addition to a tiny house, a boat, RV, or camper, or for car-camping trips, as well as inclusion in an emergency preparedness kit.

The Sun King Pro retails for $49.95, comes with a 2 year warranty, and is available at the Greenlight Planet website, or through or other online retailers. Greenlight Planet also offers a few other smaller solar LED lighting solutions, as well as a "Home" model that features three hanging lights and a central hub with a 6000 mAh battery and 6W solar panel.

[Disclosure: I received a Sun King Pro unit to review, but all opinions and any errors in this post are mine alone.]