Portable batteries have become more stylish, cheaper, smaller, and faster at charging your tech. More improvements are on the way, thanks to gallium nitride (GaN), a more space- and energy-efficient alternative to silicon that can already be found in a few wall chargers. Nice as these advancements are, they mostly impact devices with small batteries. Wall chargers aren’t much help if you’re on the go.

As more laptops and other high-powered devices adopt USB-C and move away from proprietary charging plugs, there’s an opportunity for big, powerful batteries that can augment your power adapters, and ideally, let you charge multiple devices at the same time. And now, a number of options are hitting the market aimed squarely at doing just that.

We have tested a few models that are available now, as well as some that are coming out soon. The list includes Zendure’s SuperTank, Sanho’s HyperJuice, and J-Go Tech’s Tanker Elite and Tanker Xtreme. They all have a few things in common: they aren’t small or lightweight, so your bag will gain more than a few ounces if you stick one inside. Each of these batteries has USB-C Power Delivery ports capable of delivering at least 65W of power (and in most cases, up to 100W). This means that they’re likely powerful enough to charge most laptops and replace a few wall chargers that you usually stick in your bag. Each option also has multiple ports to allow simultaneous charging of other devices. Lastly, you’ll find pass-through charging in each battery, meaning you can route power through their respective ports while the battery itself is being recharged.

These batteries do what you expect them to: charge your devices quickly, and keep them alive for longer. Cheaper battery packs suited for devices with lower power requirements do a great job of keeping phones and most tablets going for days. But if you use a Mac laptop, a new iPad Pro, a Google Pixelbook, or a Windows 10 laptop that charges over USB-C, a bigger and more powerful battery pack is a smart buy — especially if you’ll be doing some gaming, or other power-intensive activities that tend to be a quick drain on a battery.

What you get for your money

Tallying up the costs makes it clear that trying to live your life away from power outlets doesn’t come at a bargain. At the very least, your purchase will get you a battery and a USB-C to USB-C cable that can handle fast charging. Having the right cable is worth pointing out because not all USB-C cables are created equally. You’ll have to pay extra for a charger that can refill these batteries quickly, unless you find one bundled with your battery. At half the cost of the battery itself (and sometimes more) it’s worth buying one, if only for the convenience. You can certainly use a less capable USB-C charger to fill one up, but unless you’re charging overnight, it’s an insufferably slow process that will carve out way too many hours in your day.

J-Go Tech’s Tanker Elite is one of the most affordable options that we tested

At $129, J-Go Tech’s Tanker Elite is one of the most affordable options that we tested. That’s not so bad, but it’s before you factor in the cost for the necessary wall charger to quickly recharge the battery in about an hour. The 87W charger that you can purchase bundled with the J-Go Tech Tanker Elite takes just 80 minutes to recharge the entire 20,800mAh capacity. For this added convenience, you’ll need to pay a total of $164 to get the battery with an 87W wall charger included. If you want more power, J-Go Tech’s 100W charging kit sans battery is $79.99 at Amazon, and includes a braided USB-C to USB-C cable, as well as universal plug adapters. Although the Elite doesn’t have the best port selection or capacity (I’d much rather have a second USB-C port than a Micro USB port, though your mileage may vary), it will be among the most budget-friendly batteries once the other options are no longer available with crowdfunding discounts.

J-Go Tech’s Tanker Xtreme offers more capacity (27,000mAh versus 20,800mAh in the Elite) and a better port selection (a second USB-C port in place of the Elite’s Micro USB port). It’s available for purchase at Amazon with its 87W wall charger for $249.99.

At $99, the Zendure SuperTank is currently the cheapest option (the battery will jump up to $149 after fundraising concludes in June 2019), and its multi-port SuperHub charger that can recharge it at 100W speeds is another $69 (it will also go up in June to $100). Most of the batteries that we tested are shaped like big TV remotes, but the SuperTank is smaller and far more stout. This could make it a tough fit in slimmer pockets, but I’m personally fine with its design since it allows Zendure to fit in a good selection of ports, including 100W and 60W USB-C ports and 15W and 18W USB-A ports.

Zendure’s SuperHub mostly mirrors the ports available on the SuperTank. It has both 100W and 18W USB-C ports and a duo of 18W USB-A ports. If you need to charge more than one USB-C device at a time, the SuperHub is an ideal option.

Sanho’s charger is the cheapest, but Zendure’s is the best

Sanho’s HyperJuice is priced at $159 during its fundraising process, but will cost a whopping $299 afterward — and that’s not counting its 100W charger. That accessory currently costs an extra $39 at Indiegogo, but will cost $79 when it releases later this month. It’s fairly bare bones, and other than a 100W USB-C input to recharge your battery (or straight up power your device), it offers a USB-A port to keep your iPhone, or some other device, topped off.

To compare a few other USB-C chargers currently on the market, Apple’s $79 87W USB-C power charger will definitely get the job done, but obviously won’t be as fast as a 100W charger. Google’s slightly cheaper 45W USB-C charger that costs $60 will make you wait even longer for devices to recharge.

Testing out the batteries

To test these batteries, I used the Microsoft Surface Book 2 because it can charge over USB-C, and it’s notorious for demanding a lot of juice from power adapters. This laptop’s USB-C charging port pulled a maximum of 87W during testing, which I was able to see thanks to a USB-C multimeter. I performed a range of activities to see how these batteries impacted the Surface Book 2’s battery life, including powering the machine in an off state, again while browsing some websites, and lastly, while playing Sekiro: Shadows Die Twice, a game that this machine struggles to run at its native screen resolution.

All of the batteries that we tested were able to maintain and build a charge. There was one initial snag, however. The first model of Zendure’s SuperTank fell short of its advertised capabilities, topping out at a 54W output, regardless of the task at hand. The company said the unit we were testing was a prototype and sent over a finalized unit that didn’t have any issues.

Most of the time, the batteries fluctuate between 60 and 80W, depending on the moment-to-moment power requirements. And while I hacked through the endgame of Sekiro, this proved to be enough for the Surface Book 2 to slowly build a charge. When the batteries fall around the 50 percent capacity mark, I noticed a slight dip in throughput in each of them down to around 54W. While that’s not enough to charge the Surface Book 2 during gameplay, it will work to slow the drop. If you aren’t gaming or doing intensive work such as video rendering, this shouldn’t be an issue.

There were a few other quirks to note: they all exhibited a few moments when the laptop’s batteries (it houses one within the keyboard, and another in the detachable tablet) wouldn’t charge during gameplay. But hitting Alt+Tab, then shifting the PC’s power mode to “best battery life” instead of “best performance” calmed the fans down and allowed the battery to fill up — but not without some major hits to gaming performance. This is most likely a Surface Book issue.

Also, all of the batteries that I tested, at some point, made an error pop up in Windows 10 that claimed the battery was slow, or that the USB device was incompatible. Removing the plug and putting it back in usually resolved the issue, but out of the bundle of batteries we tried, the HyperJuice was the most problematic. It could be another Surface Book quirk, or it could be related to Windows 10. Other devices didn’t put up as much of a fuss, and I didn’t encounter any warnings like this when I used them to charge a MacBook Pro.

In terms of surprises, J-Go Tech’s affordable Tanker Elite surpassed its supposed 65W output limit. It was able to charge the Surface Book 2 as quickly as the others at up to 87W, which is impressive, if not a bit baffling.

Each of the batteries lasted about an hour while using intensive applications

Each of the batteries lasted about an hour while charging up the Surface Book 2. From a dead state, the 27,000mAh capacity batteries (the SuperTank, HyperJuice, and Tanker Xtreme) were able to provide about 46 percent of the laptop’s power before needing to be recharged. This might not sound like an achievement, but it’s worth noting that this laptop distributed the charge pretty evenly across its two batteries, putting equal amounts of power into the keyboard’s battery as was found in the tablet.

We also tested these batteries with a 2016 MacBook Pro and the Google Pixelbook. Both of these machines demand less power than the Surface Book 2 (61W for the MacBook Pro, 45W for the Pixelbook), and each battery easily met their maximum wattage demands. The Zendure SuperTank fully charged the Pixelbook in about 90 minutes and still had 41 percent of its battery left. If you’re using one of these batteries to stay topped off while doing some light work away from a charger, the HyperJuice was able to do so while only losing about 10 percent of its capacity after an hour of use. The other 27,000mAh batteries should give you similar results for both computers.

Which big battery is worth the money?

All of these batteries are powerful, and unless you can’t compromise even a few watts, the buying decision comes down to design preference, port selection, and of course, your budget.

For the most power for your dollar, the J-Go Tech Tanker Xtreme offers a lot of juice, a good variety of ports, and since it includes an 87W wall charger, its bundle offers the best value for your money. Zendure’s SuperTank is a great, compact package that offers the best port selection, and if you’re able to buy it for less during the fundraising, the value is good as well.

If you’re hoping to get more work done away from a wall outlet, all of them can help you do that. Each is proficient at directing a lot of power to a single device, as well as spreading it out across several at the same time, like a phone, a set of wireless headphones, and a Nintendo Switch. We expect even more options to come as 2019 proceeds, but the first batch of big, powerful batteries is impressive.

Buy the J-Go Tech Tanker Xtreme: Amazon | J-Go | Google Shopping