In April 2024, a MacBook Pro owner on the ComputerBase forum thought his new Anker 737 had lost about 12,000 mAh somewhere. He had charged the bank to 100 percent, then topped up a 14-inch M1 Pro from about 27 percent while browsing, and the bank fell to 21 percent. By the numbers on the box, that seemed far too much. The bank was fine. The numbers on the box were the problem, and I think that thread teaches more about this product than any spec sheet.
Owner reports are few, so I lean on two hands-on reviews and say when I do. One of those reviewers received the unit free from Anker, which I note below.
Product image from the Amazon listing.
Why 24,000 mAh Does Not Mean What You Think
The commenters in that forum thread gave the right answer. You can’t compare mAh figures taken at different voltages. The 24,000 mAh rating refers to the cells inside. The honest figure is energy in watt-hours, and for the 737 it is 86.4 Wh. A 14-inch MacBook Pro of that generation holds 69.9 Wh, according to one commenter there, so the bank is only a little larger than the laptop’s own battery. Before you count on anything, think in watt-hours.
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Then there are losses, because energy gets burned as heat on the way through. Sir Apfelot, a German Apple site whose unit came free from Anker, ran a useful test. Over 20 minutes, a 14-inch MacBook Pro with an M1 Max gained about 34 percent while the bank lost about 42 percent. If you stretch that ratio out, a full bank would give about 80 percent of one full charge to that laptop. That is my arithmetic from a single short run, and the laptop’s own use during the test is mixed in, so take it as a rough guide. I would still plan on less than one full MacBook Pro charge from this bank in real use.
Smaller Macs do better. A commenter in the ComputerBase thread estimated about 1.3 charges for a 2020 M1 MacBook Air, working from maker data. So if you travel with a MacBook Air, this bank can carry you through a long day. If you have a 16-inch MacBook Pro with its bigger battery, expect a good top-up and nothing more.
Mighty Gadget offers a phone-based check. Charging a 4,500 mAh phone from flat to full left the bank at 74 percent, and the reviewer worked that out to roughly 17,300 mAh in total. That review concludes that the bank appears to hold what Anker claims. Note the gap, though: a 24,000 mAh label turned into a practical figure of about 17,300 mAh, even in a test that called the result good. That is normal for power banks, and it is why I would never buy one by the label alone.
The 140W Promise Needs the Right Parts
The headline number is real, but it has conditions. Anker’s page lists 140W maximum total output, with each USB-C port able to reach 28V at 5A, and it says you need a PD 3.1 cable to reach 140W. It also says a USB-C to MagSafe cable is the best choice for some uses, so check that page against your own Mac.
Real Mac draw was lower in the hands-on tests. Sir Apfelot saw 85 to 93 watts going into the 14-inch M1 Max. Its charging speed still impressed the reviewer, who called it breathtaking, and that laptop gained a third of its battery in 20 minutes. An older 12-inch MacBook pulled only 28 watts, its own limit, gaining 14 percent over the same time. The bank offers power. The Mac decides how much it takes.
Anker’s claim of 50 percent in about 40 minutes for a 16-inch MacBook Pro comes up in several reviews. Mighty Gadget says plainly that it could not test this, as the reviewer had no 140W device. I found no independent measurement of that claim, so please treat it as Anker’s number. Windows laptops vary as well. Mighty Gadget saw a Huawei MateBook 13 peak at 65 watts.
Cables decide a lot here. Sir Apfelot notes that most charging cables do not support 140 watts. Mighty Gadget measured this on the input side: a 140W cable and charger typically reached 120 watts when refilling the bank, a 100W Ugreen cable reached 90 watts, and a 60W Anker cable gave 53.2 watts. Note what that means. A weak cable from your bag quietly turns a fast bank into a slow one, and you may not notice.
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Product image from the Amazon listing.
Refilling the Bank Is Its Own Trip
Refill speed matters as much as output when you are moving between hotels. The bank charges through one USB-C port at up to 140W on paper. Mighty Gadget’s best result was typically 120 watts, which it called a bit short of the advertised figure. Fine for most people, but you do need a charger that strong. That review also warns that Anker’s own 737 charger in the UK tops out at 100 watts. A small 65W laptop charger will refill this bank far more slowly. Sir Apfelot’s kit included a charger of exactly that size. Plan for it, or keep the bank topped up overnight.
The Screen Earns Its Space
Most power banks show you four dots. The 737 has a small color display showing battery information, and Anker lists screen time, battery cycles and total input and output among its readouts. I think this is the most useful feature on the product for a Mac user. Every question in this review comes down to how much energy went where, and a running total of input and output is the closest thing you get to an answer without a separate meter.
Product image from the Amazon listing.
Size, Weight and the Small Stuff
The 737 weighs 630 g, or 22.22 oz, and measures 6.13 by 2.15 by 1.95 inches. That is heavy for something you carry on top of a laptop. It will go in a backpack. It will not go in a jacket pocket. Sir Apfelot also found the included fabric pouch gives little protection in transport.
You get three ports, two USB-C and one USB-A. Mighty Gadget found that “a bit less than I’d like to see” at the price, which it called “undeniably expensive.” Sir Apfelot said it was the most expensive power bank it had tested at the time. Anker’s USB-A port is slower by design. Use it for earbuds or a phone.
For flying, 86.4 Wh sits under the 100 Wh limit that US airlines commonly apply to batteries carried on board. That is a good reason to choose this size over something bigger. Rules vary, so check with your airline first, and keep the bank in your hand luggage.
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One gap I should state. I found no long-term owner reports on how the cells hold up over years, or on failures. The owner thread covers the first few days only. With a product at this price, that is a real unknown.
Buy It for Speed, Not for Endless Power
I would recommend the Anker 737 to one type of person: a MacBook user who needs a fast top-up during a day away from outlets, and who will carry the right cable and a strong charger. For that person, the speed Sir Apfelot saw is the point of this product, and the screen makes the whole system easy to understand.
Skip it if you expect several full MacBook Pro charges, as the numbers do not support that. Skip it if you only need to charge a phone or a MacBook Air at modest speed, because a lighter and cheaper bank will do. And if your laptop tops out at 65 watts, you are paying for power it can’t use.
For the right traveler, the Anker 737 Power Bank 24000mAh is a strong but heavy tool, so plan your trip around its watt-hours and bring a cable rated for the job. This is an affiliate link. As an Amazon Associate I earn from qualifying purchases.
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