With the Anker Nano Power Bank (5K, MagGo, Slim), thin is definitely in. Measuring just 0.34 inches deep, the Qi2 power bank attaches magnetically to MagSafe iPhones and delivers enough juice to get you through a frantic afternoon on the go.
At just 5,000 mAh, it won’t take modern iPhone batteries all the way to 100%. But it will power up a dead iPhone from zero to 20% in a little over 20 minutes. And it does so while attached comfortably to the phone, without the excessive heat generated by some competing power banks.
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Anker Nano Power Bank review
This incredibly slim Qi2 power bank gives your iPhone a power boost without the bulk. Plus, it stays cooler than competitors. While it can't recharge an iPhone to 100%, this barely-there charger will get you through the day.
- 15W wireless fast charging
- Just 0.34 inches thick
- Weighs only 4.2 ounces (119 grams)
- Slightly slower than the latest Qi2.2 chargers
Most power banks turn your iPhone into an unwieldy brick when you attach them. Or, worse, they make it seem like your iPhone is attached to a brick by a cable.
Not Anker’s new Nano Power Bank (5K, MagGo, Slim). The power bank’s name is far more unwieldy than the gadget itself.
When I pulled it from the box and put it on my iPhone 16 Pro, I was immediately impressed by how incredibly slender the power bank is. My CultCast colleague D. Griffin Jones enjoyed the same experience, and so did everyone I showed it to. Most people had never seen a power bank as unobtrusive as Anker’s latest (at least until Apple unveiled its iPhone Air MagSafe Battery during its Awe Dropping launch event earlier this month).
That feeling persisted when I used the Anker Nano Power Bank in the wild. It’s so small, lightweight and smoothly designed that it doesn’t make much of an impact. With it attached to my iPhone, it felt like a single unit. And it slid easily into the pockets of my jeans.
At 5,000 mAh, it’s enough to get you through a tough spot
Photo: Lewis Wallace/Cult of Mac
The power bank’s svelte size makes it perfect to slap on the back of my iPhone when heading out the door with a worrisomely low charge. (This happens more often than I’d like to admit.) And the strong magnets pop it into place on the back of my phone and hold it there securely.
The small, lightweight form factor also makes it great to toss in a backpack or travel duffel when heading out for a long day of planes, trains and automobiles, when excessive iPhone use would typically find me searching for a place to plug in and recharge.
This little wonder frees me of the tyranny of the electrical outlet — and that horrible feeling that my iPhone might run out of juice and I might (gasp!) be unable to look at Slack or X or any of the other apps I’m basically addicted to.
However, as mentioned, it’s not enough to recharge an iPhone from zero to 100%. Even though its 5,000 mAh rating tops the capacity of today’s iPhone batteries, the inherent inefficiency of wireless charging means this little power bank is purpose-built to get you out of a low-power jam.
Anker lists the maximum charging levels for various models on its website: iPhone 16 Pro (80%), iPhone 16 Pro Max (63%), iPhone 15 Pro (91%), iPhone 15 Pro Max (65%), iPhone 14 Pro (91%) and iPhone 14 Pro Max (70%). Specs for the iPhone 17 series don’t show up yet.
Design: So thin, so light, so cool to the touch
When it comes to design, the main attribute of the Anker Nano Power Bank (5K, MagGo, Slim) is, once again, its thinness. It measures just 4.02 inches by 2.78 inches by 0.34 inches. According to my scale, it weighs just 4.2 ounces (119 grams). And it fits beautifully on the back of my iPhone 16 Pro and my new iPhone 17 Pro.
My colleague D. Griffin Jones says it works great on an iPhone Air, too. In fact, this is the iPhone battery pack that Apple should have made. Instead of only fitting the iPhone Air, this one fits all MagSafe iPhones. And at $54.99 (versus the iPhone Air MagSafe Battery’s list price of $99), it’s quite the bargain.
Available in black, white, green and golden, its edges are nicely rounded. Its metal back feels great in the hand when attached to my phone, and isn’t too fingerprint-prone.
Cooler than competitors
Photo: Lewis Wallace/Cult of Mac
Speaking of feeling good in your hand, Anker touts the Nano Power Bank as running 14 degrees cooler than the industry standard. The company says the device will reach a maximum temperature when in use of 104 degrees. (Anker cites the industry standard as 118.4 degrees.)
In my testing for this review, the Anker Nano Power Bank never got as hot as my iPhone 16 Pro usually did when performing processor-intensive tasks. I took several measurements with an IR thermometer gun while charging my phone. The power bank never went higher than 100 degrees.
A USB-C port on the bottom of the power bank allows for 20W fast charging when refilling. It can go from zero to 100% charged in less than two hours with an appropriate charger.
As is typical for slim devices like this, four round white LEDs show the power bank’s battery level when in use or while plugged in to recharge. A digital readout would be slightly more comforting, but would add to the thickness of the slim power bank.
A couple of nitpicks
As mentioned, this is a Qi2 charger, so it maxes out at 15W wireless charging. Some new Qi2.2 power banks hit 25W for slightly faster wireless charging. However, that’s a newly implemented standard, so they’re few and far between. (You’ll find the Anker Nano Power Bank from this review, as well as a couple of faster Qi2.2 models, in our list of the top 10 power banks for Apple users in 2025.)
One nitpick I have is the Anker logo on the back of the power bank. I love the incredibly understated black-on-black look, but I find the positioning weird. When attached to an iPhone, the Anker logo runs north and south, which makes for a slightly odd look. (I guess it’s fine if you’re streaming something in portrait mode, but it seems like it would have been better to align the logo with its top facing the top of the iPhone, the way the Apple logo does.
Side note: My colleague Griffin found the regulatory info that runs around the edges of the power bank a bit off-putting. I barely noticed it, and definitely can’t read it (even up close). That said, Griffin’s suggestion that it could be printed on the power bank’s magnetic charging face so it never shows while attached to a phone might make sense. Then again, it might be even more visible if located there.
Anker Nano Power Bank (5K, MagGo, Slim) review: Conclusion
Bigger power banks offer more power. Wired power banks offer more efficient charging. But that’s not what the Anker Nano Power Bank (5K, MagGo, Slim) was built for. Anker built it to get you through a busy afternoon where you forgot to charge up your iPhone before leaving the house or burned through your phone’s battery while doomscrolling.
The barely-there battery pack is super-slim, lightweight and easy to slide into a pocket or slap on the back of your iPhone. It’s the iPhone battery pack Apple should have made instead of the pricier iPhone Air MagSafe Battery, which only works with one model.
If you own an iPhone — or a Qi2-compatible Android device — and you suffer from nomophobia, don’t leave home without it.
★★★★★
Buy from: Amazon
This incredibly slim Qi2 power bank gives your iPhone a power boost without the bulk. Plus, it stays cooler than competitors. While it can't recharge an iPhone to 100%, this barely-there charger will get you through the day.
- 15W wireless fast charging
- Just 0.34 inches thick
- Weighs only 4.2 ounces (119 grams)
- Slightly slower than the latest Qi2.2 chargers
Anker provided Cult of Mac with a review unit for this article. See our reviews policy, and check out other in-depth reviews of Apple-related items.
