Whether you love camping because you enjoy the wilderness or just want to escape the imminent collapse of society, you'll want some electrical power while you're gone. It needs to be light enough to carry around, able to power small appliances, and should include a solar charge controller in case you're going to be out there for a while. An emergency light would be the icing on the cake.

Maxoak has exactly what you're looking for, with its Bluetti AC50S.

We're no stranger to Maxoak backup batteries here at MakeUseOf, having previously reviewed the massive EB240 and AC100. But those are difficult to carry around unless you have transport and more suited to use in caravans and cabins. At 13.5lbs, the AC50S certainly isn't lightweight but could still be heaved up a hillside without requiring a trip to the hospital.

With a total capacity of 500Wh, an AC converter, and a built-in MPPT solar charger, it'll go all day and then some.

Join us as we take a closer look at the AC50S, and thanks to Maxoak, we have two of these incredibly powerful emergency batteries to give away to two lucky readers. You'll find the competition entry form at the end of this review. 

But first, let's look at some of the standout features of the AC50S that make it perfect for camping and emergencies.

10W Wireless Qi Charging Pad

Your smartphone is probably the most important item you have during an emergency, so it's critical that you can keep it powered up. If you've lost or damaged the charging cable, you're in trouble.

Not so with the Bluetti AC50S, which includes a 10W wireless Qi charging pad on the top. To use it, turn on the main power and the DC output, then put your smartphone or tablet down (though some devices charge better when placed off-center, depending on where their Qi receiver is embedded).

Any smartphone from the last three or four years should be Qi-enabled, so this could be a real lifesaver. While it usually won't charge as fast as a cables, it's certainly more convenient.

Emergency SOS Flashlight

Built-in to the rear side of the AC50S is a large LED lighting panel. It features two brightness settings and an SOS mode. The exact lumens brightness isn't published, but the highest setting is bright enough to be painful to look at directly. The handle is positioned in such a way that the light can face forward when carried normally, so you needn't take a separate flashlight on your travels.

The SOS mode is something we hope you'll never need, but it's reassuring to know it's there if you do. In this mode, which operates at full brightness, the morse code for SOS is continuously repeated.

For either mode of operation, the AC50S must be powered on first, then the flashlight activated.

Bluetti AC50S Design

Measuring 11.6 x 7.5 x 7.7 inches and weighing 13.5lbs, the Bluetti AC50S sits at the extreme of what could be considered easily portable. The carry handle easily unfolds from its inset position in the lid and feels quite comfortable to hold without digging into your fingers. I would happily take this on a short hike, but hours of trekking around with it would certainly get tiring.

The corners of the AC50S are softened with a thin blue rubber bumper, and along with four rubber feet, ensure it can take the hustle and bustle of an outdoor camping trip without damage. It also means if you knock the relatively large device into your legs or waist when carrying it, the blow might be softened a little.

 

Don't mistake these rubber bumpers for proper ruggedization, though. As with all large battery packs, the AC50S should not be thrown into a fire, pierced, shot, dropped off a cliff edge, or fed to a bear. The multiple power sockets and cooling grills also mean it isn't waterproof in the slightest. However, it is apparently made from flame retardent plastics, so you needn't worry about placing it in the general vicinity of a campfire. Not too close, though.

A clear dual-color LCD shows the remaining battery as five segments (each helpfully labeled in 20 percent increments), as well as the total wattage currently coming in and going out, with AC and DC reported separately. Though you're unlikely to hit the maximum 300W if you're only charging laptops and smartphones, this information does allow you to make a quick calculation of how long the battery will last.

Sockets, Ports, and Plugs Galore

Considering the diminutive size of the Bluetti AC50S, there's a bewildering number of sockets to be found.

There are four USB-A ports, each running at a maximum of 3A. Sitting above them is a single USB-C PD port, running at a maximum of 45W. This is slightly lower than most laptops' power requirements when running full speed but should be enough for light tasks or charging with the lid closed (if you didn't bring your AC adaptor, that is).

You'll find two small barrel-jack DC ports on the right of the display, running at 12V, 3A maximum. Further right of this is the regulated 12V car accessory port (or cigarette lighter, as we call it in the UK).

As we reviewed the UK model, you'll also see two three-prong UK plug sockets, which run at ~240VAC. A European model and US model is also available, running at ~110VAC. The maximum continuous output in either model is 300W, 450W peak.

How Long Will It Take to Charge?

The included AC wall charger is 90W, so this will charge in approximately six to seven hours. Also included in the box is a charging cable for use with your car battery from the 12V port.

Solar input is limited to 120W, with an open-circuit voltage of up to 40V. Although an adaptor cable for industry-standard MC4 solar connectors is included, these limitations mean most static panels (such as those taken from a rooftop install) can't be used. Of course, the AC50S is designed to be portable, so this isn't a big deal. For static installations, you should look at the larger Maxoak backup batteries.

Thankfully, Maxoak also sells a portable solar panel perfectly matched to the input rating of the AC50S. We reviewed the SP120 a few months back. Under ideal conditions, the SP120 could charge the AC50S in as little as four to five hours, faster than the AC adaptor. Realistically, it would likely take six hours to a day, given varied cloud cover, the angle of the sun, and other factors.

You can charge and discharge the Bluetti AC50S simultaneously without issue.

Is 300W Continuous and 450W Peak Enough for You?

300W is plenty enough to power laptops, smartphones, tablets, and other USB devices—all at the same time. If that's your intended use case, you needn't worry about the peak rating.

But if you plan to use the AC sockets, you should take note of it. Most small appliances will comfortably run on less than 300W continuous. Still, some such as air conditioners or fridges will surge to five or seven times their rating momentarily when switched on. If they exceed 450W, the Bluetti AC50S will display error 27 and require a restart. Therefore, you must know the peak or surge rating for any appliances you hope to power with the AC50S.

In some cases, there may be a workaround, so you can still use the appliance. For instance, set your coolbox or mini-fridge at room temperature first when switching it on, then slowly decrease the temperature. If your appliance surges beyond 300W but less than 450W, this should be fine as long as it doesn't continue for more than 120 seconds.

How Long Will The AC50S Battery Power Last?

To work out how many hours the AC50S will last you, divide the capacity (500Wh) by the power you're expecting to draw. For example, a 50W CPAP machine could run for around 10 hours. If you're unsure, plug in the device: the helpful indicator on the front of the AC50S will tell you exactly how much power it's using, from which you can calculate. Bear in mind this value may fluctuate. For instance, when I tested a deep freezer, it varied anywhere from 5W to 110W.

For devices like a smartphone, it's more helpful to think about how many charges you'll get from the AC50S. An iPhone 12 could be charged anywhere from 20 to 40 times; a typical laptop will get at least seven charges.

Do You Actually Need "Regulated" 12V?

If you're shopping for backup batteries based purely on color, or if you don't care about the 12V car port output being regulated, then I've got good news: the previous AC50 model comes in orange or grey, and is available for as little as $350 (use the coupon code MAXOAK100 to get that extra $12 off). The only difference (other than color) is that the 12V output is not "regulated." That means you might not quite get 12V. You might get 11V or 11.5V. For some appliances, getting at least 12V minimum is critical, and without that, they won't power on. For others, it won't matter. And if you're not going to use the 12V at all, it obviously doesn't matter.

Portable, Powerful, Perfect for Camping

The Bluetti AC50S is easy to operate, packs a huge amount of power into a small package, and includes lifesaving features like an emergency light and wireless Qi charging–all at a budget-friendly price of under $500. There's a lot to like about the AC50S, and if we had a single complaint, it would be that the AC converter is slightly limited at 300W continuous, with 450W peak meaning some appliances won't work.

Still not convinced? We've secured some special coupons to help you decide:

• Purchase the Maxoak Bluetti AC50S in the US - use code bluetti50s for an extra 3% off (combine the Amazon discount for a total of $42 off)
• Purchase the Poweroak Bluetti AC50S in the UK - use code bluetti2 for £50 off
• Purchase the Poweroak Bluetti AC50S in Germany - use code bluetti 2 for €50 off

Thanks to Maxoak, we have two Bluetti AC50S backup batteries to give away. This competition is open to the UK, Europe, and North America; just enter below for your chance to win. Remember to add competitions@makeuseof.com to your address book, so you don't miss our email about claiming your prize!