Gear Closet: Energizer PowerKeep 36 Solar Charger and Battery Pack Review

Over the past few years, we’ve seen solar charging become more of an option for our backcountry needs. This is partly because solar panels continue to get more efficient and lightweight all of the time, making them more viable options for keeping small devices like a smartphone or a camera charged while living off the grid.

At this point, there are literally dozens of options available for travelers and backpackers looking to stay powered up while on the go, making it a challenge to sift through which ones are actually useful and which ones are actually just dead weight.

The latest company to throw its hat into the solar-charging ring is Energizer, which has just launched its own line of solar devices that include portable chargers as well as backpacks with solar panels built-in. I’ve recently been testing the new PowerKeep 36, which is an all-in-one solution for those who need to keep small electronics functioning while traveling off the grid.

The PowerKeep 36 includes pretty much everything you need to start using solar energy to power your gadgets. It includes a four-panel, fold-out solar panel capable of generating up to 5 watts of power and direct 1.2 amps to its built-in USB port.

The kit also includes a 10,000 mAh battery pack to store the power collected by the panel and save it for when you want to recharge the batteries on your mobile device—an included standard USB cable rounds out the package.

The portable solar panel itself is surprisingly lightweight (10.3 ounces/293g), thanks in part to the flexible materials that it is constructed out of. This makes it easy to slip into a pack and take with you just about anywhere, and since it doesn’t use a glass-backed panel, you don’t have to be especially careful with it. When folded down, it has a small footprint and expands out nicely when it’s time to place it into the sun.

As with all solar panels, the amount of power you can generate will vary widely depending on a few variables. They all work most efficiently when placed in direct sunlight, and the PowerKeep 36 is no different.

On bright, sunny days, with a clear view of the sun overhead, it was indeed able to generate a solid current that could be used to charge a smartphone or the included battery pack. But, throw in a bit of cloud cover or shade, and efficiency dropped off dramatically.

This is something that I’ve seen in nearly every solar panel I’ve tested, so it is not unexpected. But, because the PowerKeep 36 doesn’t generate a great deal of power, to begin with, it needs to be in almost optimal conditions to truly function at its best.

The included USB battery pack is probably my favorite part of the entire kit. It tips the scales at 8.4 ounces (240g) but packs enough power to recharge most smartphones 3-4 times before it needs to be topped again. I appreciate its lean profile and relatively small size, which makes it a nice option for travelers, whether they are bringing the solar panel or not.

Since it has two USB ports, it is capable of charging multiple devices simultaneously. The power bank includes four LED lights to indicate its current charge level and comes with a built-in USB cable as well.

The best way to use the PowerKeep 36 is to leave the solar panel spread out on the ground in the direct sunlight at your campsite with the battery pack plugged in at all times. This allows it to collect and store power for the maximum amount of time.

Efficiency once again drops off dramatically if you attach the solar panel to a backpack and wear it with you while hiking. While it will collect some power this way, it will literally take days to refill the 10,000 mAh battery.

Even in direct sunlight, I still found that the PowerKeep 36 was slow to charge. But when paired with the USB charger, it worked reasonably well, allowing me to power my iPhone for several days longer than normal while traveling off the grid.

Without direct sunlight, however, the battery pack can’t keep up with the demands placed on it from a smartphone, and after a few days, I noticed that it was losing juice at a faster rate than it was taking it in. Again, this isn’t unique to the PowerKeep 36 and is more of an issue with solar panels in general right now. They do work, but you have to accept their limitations even as companies strive to improve newer models.

Priced at $169, I feel the PowerKeep 36 is a bit of a mixed bag. Solar panels from Goal Zero are less expensive, generating more power, making them a tempting alternative. Of course, those panels don’t come with a USB battery pack, and they are also heavier and less flexible too, so there are some trade-offs in both directions.

If you’re looking for a lightweight, easy to use, solar charging solution straight out of the box, Energizer’s offering is a solid choice. Just be aware of the limitations of using these panels ahead of time and plan accordingly.