Power banks have exploded in popularity over the past few years, but they've also been steadily dropping in price and capacity. We're slowly reaching the point where it's not feasible to just keep increasing the capacity of the battery while chipping away at the price, so some companies are venturing out into new features for their portable batteries.
ZeroLemon's take on this involves baking a solar panel into the top of an enormous battery, and that's how we end up with the SolarJuice power bank. Not only can you charge this thing with your standard micro-USB chargers, but you can also leave it out in the sun to juice up on its own, too. It's a neat concept, but does it work well in day-to-day usage?
The power bank itself is fairly bulky but well designed. The sides are made of hard plastic, but it feels extremely durable. I'm sure some of that is due to the weight, but I wouldn't worry at all about dropping and breaking this thing. It weighs about 1.2 pounds according to the listing on Amazon and the dimensions measure 5.7 x 2.9 x 0.5in.
The sides are a bright yellow, which lends itself to being suited for outdoor use. It's bright and sticks out, so you won't lose it despite the solar panel and rear being nearly pitch black. The top features a tiny handle so you could strap the power bank to something else, with the bottom featuring an LED flashlight and two charging ports. The flashlight button is on the left side towards the bottom, and the charging input port is on the right side towards the bottom.
Here's the good and the bad; this thing is huge. I reviewed the 20,000mAh version of the SolarJuice battery — they come in 6K, 8K, 10K, and 20K sizes. So I got a chance to carry around the biggest SolarJuice model that ZeroLemon makes. Like any other 20,000mAh battery, it's got some considerable size to it, but that also means it's got plenty of juice to last you and your smartphone several days.
When you actually get a chance to use this power bank, you'll understand that “days” is almost an understatement. Over a weekend beach trip with near constant use, the battery sat somewhere between 50% and 75% the entire time, and that's with charging more than one phone over several hours, sometimes simultaneously. Impressive is an understatement. Part of that is due to the sheer size of the battery, but some of it thanks to the constant solar charging that's going on.
There are other smaller and thinner portable batteries of this capacity on the market, but in order to maximize the efficiency of the solar panels on the top of the power bank, ZeroLemon had to keep the size up a bit. Unfortunately, those solar panels only provide a 0.2 amp charge as opposed to a plugged in 1 amp charge or a high speed 2.1 amp charge.
If you want to take rough estimates at how long it's going to take to charge things, a 1 amp charger that ships with most smartphones will take about 20 hours to get this thing juiced up from 0 to 100. A faster, 2.1 amp charger would obviously cut that time drastically, but since the big selling point here is the solar charging, that's where the focus is.
Since the solar panels are only able to pull in 0.2 amps, that quintuples the charge time from completely dead to completely charged. You'd have to leave this thing in the light for over four days to get it completely charged up, which is pretty unfeasible no matter how you slice it.
I know, I know, that sounds bad. Four days to charge a battery? You're probably thinking there's no way you'd ever want one of these. And if you're looking for a power bank to carry around to a bar or somewhere without much light, you're right, it'd probably be pretty useless. But in a situation where you're at the beach, or staying outside for a big chunk of time? That's part of the reason why I never had to charge it.
On a beach, the battery is almost always charging. If you're hiking, or sitting at a park or at a picnic, it'll constantly charge. Anytime you're outside (or inside, if you're sitting near bright light or near a window) it's going to constantly charge up. It's not a quick charge, but spending extended periods of time in the sun is basically a free charge. And since it's already a huge battery, you're very likely not going to run out of juice within a day or two of use. Theoretically, you could use this battery every weekend while leaving it next to a window during a week and you'd have a portable battery that you'd literally never have to charge. And in a pinch, just use a high-speed charger to get it juiced up overnight.
I wouldn't say this power bank is for everyone, but if you're the kind of person to benefit from it, you're really going to like it. The bright yellow aesthetic and handle make it great for carrying around, and the LED flashlight gives it some extra utility. If you spend a ton of time outdoors, it's a huge battery that's going to constantly (albeit slowly) recharge itself to give you a little extra oomph to get through your weekend adventures. I could easily see this working out for someone with an action camera, too.
At $39 it's not the cheapest 20,000mAh power bank you'll find, but it does have some extra functionality and ZeroLemon's 36-month guarantee. If you frequently spend weekends outdoors at the beach or anywhere similar, you'll be hard-pressed to find a better accessory to bring with you. If you're more of a bar hopper or night owl, though, I'd grab something cheaper and without the solar charging.
[Amazon]