Desk & Power review
Anker 737 Review: 24,000mAh on the Box, About 13,000 in Practice
140W means a MacBook Pro charges at close to wall speed. Conversion losses mean you get roughly half the headline capacity, which is normal and almost never said out loud.
By Paulo GerchonPublished 2 min read
Illustration, not a photo — we don’t have a licensed image of this product yet.
Anker
Anker 737 Power Bank
Good · researched from 4 sources
The power bank to buy if a laptop is what you need to charge, because 140W in and out is what separates it from cheaper bricks. Plan around roughly half the printed capacity, which is physics rather than a defect, and do not expect to carry it in a pocket.
- Buy if
- Laptop users who need a real charge rather than a top-up · Travel, where 86.4Wh clears airline carry-on rules · Anyone charging a laptop, tablet and phone from one brick
- Skip if
- Pockets, at 630 g · Anyone who only ever charges a phone · Buyers expecting 24,000mAh of usable output
We don’t list prices, because Amazon’s change hourly.
The number on the box is not the number you get
Cubed3 did something most power bank reviews skip: they worked out what actually comes out.
The cells hold 24,000mAh. After the conversion from cell voltage to the 5V or 20V your device wants, roughly 13,000 to 14,000mAh reaches the device. That is a loss of about 40 percent.
This is not a fault and it is not specific to Anker. Every power bank does it, because stepping voltage up or down wastes energy as heat, and the industry prints the flattering number because everyone else does.
The figure that does not lie is the watt-hour rating, here 86.4Wh, because watt-hours already account for voltage. If you are comparing banks, compare those.
What 140 watts is for
Almost every power bank you can buy caps somewhere between 60W and 100W. At 60W a large laptop charges slowly, and if you are using it at the same time, sometimes not at all.
At 140W, Cubed3 reports it charging demanding laptops such as the MacBook Pro at full speed. That is the entire argument for this over something cheaper and lighter.
It takes 140W in as well, so the bank itself refills at laptop speed rather than needing an overnight session. On a trip where you charge the bank while you sleep and the laptop while you work, that symmetry matters more than it sounds.
The display earns its place
Most power banks tell you the state of charge with four LEDs, which means you know it is somewhere between half and three quarters.
Cubed3 describes a screen showing real-time input and output wattage, battery percentage and cycle count. Watching it report 140W tells you your cable and charger are actually up to the job, which is the single most common reason fast charging silently is not happening.
Their caveat is that leaving the display running, or leaving cables plugged in, contributes to idle drain. A bank that goes flat in a drawer is a familiar annoyance and this one is not immune.
The weight is the trade
About 630 grams, 155.7mm long, and Cubed3 calls it impractical for pocket use. MacSources, who liked it enough to score it 90 percent, still wished it were more compact.
That is what 86.4Wh of cells and the circuitry to move 140W weighs. There is no version of this product that is both this powerful and pocketable, and if you only ever charge a phone you are carrying half a kilo for no reason. Robb Sutton puts real-world phone charges at five to six, which is more headroom than most people need.
Small things
The USB-A port tops out at 18W per MacSources, so it is there for the cable you already own rather than for speed.
There is no wireless charging, which Robb Sutton lists as a downside. On a brick this size that is a reasonable thing to want and a reasonable thing for Anker to have left out, since wireless charging is the least efficient way to move energy and this product is otherwise built around not wasting it.
How it scored
The overall 7.8 is the weighted average of these five criteria — we never adjust it by hand.
Charging performance
140W Power Delivery 3.1 out and the same in. Cubed3 reports it charging demanding laptops at full speed and running three devices at once.
Value
Cubed3 scored it 9 out of 10 and MacSources 90 percent, both while listing the premium price as the main objection.
Build quality
MacSources ran a 30 minute charge test and found the bank stayed cool, dropping only 10 percent. Robb Sutton notes a matte finish that resists fingerprints.
Ease of use
The display is the standout. Cubed3 describes real-time input and output wattage, battery percentage and cycle count rather than four vague LEDs.
Portability
About 630 g and 155.7 mm long. Cubed3 calls it impractical for pockets and MacSources wished it were more compact.
Pros and cons
What we liked
- 140W output, enough that Cubed3 found it charging demanding laptops at full speed
- 140W input too, so the bank itself refills quickly
- A display showing real input and output wattage, battery percentage and cycle count
- At 86.4Wh it stays under the 100Wh airline carry-on limit
- MacSources found it staying cool through a sustained charge test
What we didn’t
- Cubed3 puts real delivered capacity at roughly 13,000 to 14,000mAh after conversion losses
- About 630 g, which Cubed3 calls impractical for pocket use
- Cubed3 reports idle drain if you leave cables connected or the display active
- The USB-A port is limited to 18W per MacSources
- No wireless charging at all, which Robb Sutton lists as a downside
Specifications
| Rated capacity | 24,000 mAh, 86.4 Wh per Cubed3 |
|---|---|
| Real delivered | About 13,000 to 14,000 mAh after conversion losses per Cubed3 |
| Maximum output | 140 W, Power Delivery 3.1 |
| Input | Up to 140 W, bi-directional |
| Ports | 2 x USB-C output at 140 W max, 1 x USB-A at 18 W max per MacSources |
| Display | Digital, showing input and output wattage, percentage and cycle count |
| Weight | About 630 g per Cubed3; 1 lb 6.1 oz per MacSources |
| Dimensions | 155.7 x 54.6 x 49.5 mm per Cubed3 |
| Airline | Under the 100 Wh carry-on threshold |
How we researched this
We have not had this unit on the bench. This review synthesises the manufacturer’s published specifications, independent measurements and owner reports listed below. Every figure on this page comes from one of those sources rather than our own measurement.
4
sources reviewed
Cubed3 supplies the watt-hour rating, the dimensions, the conversion-loss estimate and the idle drain observation, and is the only source that addressed the gap between rated and delivered capacity. MacSources ran a timed charge test with a phone and earbuds and reported thermal behaviour and the per-port wattage limits. Robb Sutton contributed real-world charge counts and the absence of wireless charging. Anker's own product page was not read, so every figure here is attributed to a reviewer. Where MacSources and Robb Sutton give different weights, about 626 g against roughly 1.5 lb, we have used the two that agree.
What we read
Common questions
Why does a 24,000mAh power bank not deliver 24,000mAh?
Will it charge a MacBook Pro at full speed?
Can I take it on a plane?
How many phone charges will I get?
Is the display worth anything?
The bottom line on the Anker 737 Power Bank
The power bank to buy if a laptop is what you need to charge, because 140W in and out is what separates it from cheaper bricks. Plan around roughly half the printed capacity, which is physics rather than a defect, and do not expect to carry it in a pocket.
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