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The Anker Nano 10K review starts with a problem most buyers do not know they have: there are two versions of this power bank on Amazon UK right now, they look almost identical, and they charge your devices very differently.
One is the A1259, the older 30W model with a fixed cable, priced around £26 to £30 at time of writing (March 2026). The other is the A1638, the current 45W model with a retractable InstaCord cable, priced around £37.99. Both are good. But they suit different buyers, and picking the wrong one is an easy mistake to make.
This review covers both. We will tell you what each one does well, where each one falls short, and exactly which one to buy based on how you actually use a power bank.
Which Anker Nano 10K are we talking about?
Before anything else, here is the difference side by side. Prices are correct at time of writing (March 2026), check Amazon UK for current pricing.
| A1259 (30W) | A1638 (45W) | |
|---|---|---|
| Max output | 30W | 45W |
| Cable | Fixed, non-retractable | Retractable InstaCord, 70cm |
| UK price (March 2026) | approx £26–£30 | approx £37.99 |
| Weight | approx 215g | approx 232g |
| Warranty (UK) | 24 months | 18 months |
| Cable durability | Not rated | 20,000 bends and pulls |
| Best for | Budget buyers, phone-only use | Faster phones, travel, everyday carry |
If you are buying new and want the best version, the A1638 is the one. If budget is the priority and you mainly charge a phone, the A1259 does the job for less. We will cover both properly below.
Anker Nano 10K (A1259, 30W) – the budget version
UK price at time of writing (March 2026): approx £26–£30
The A1259 is the version that made the Anker Nano a popular name. It is compact, it has a built-in USB-C cable, and it charges phones quickly enough for most people.
The cable is fixed rather than retractable. That means it folds out from the body of the bank and stays out until you fold it back. It is less elegant than the A1638’s InstaCord but it works and it has been reliable in long-term use.
At 30W maximum output, it will fast-charge most modern iPhones and Android phones. Not at the absolute peak speeds those phones are capable of, but noticeably faster than a cheap 5W charger. An iPhone 15 will gain roughly 50 percent in around 30 to 35 minutes.
At approximately 215g it is lighter than the A1638. The 24-month UK warranty is also longer than the A1638’s 18-month cover, which is worth noting if you tend to keep gear for a long time.
What it cannot do: Fast-charge newer phones at full speed. The A1638’s 45W is meaningfully faster for iPhone 16, Samsung S24, and similar devices. The fixed cable is also less convenient for travel than the retractable design.
Who it is for: Phone-only users who want a compact backup bank and do not need maximum speed. Good first power bank. A sensible gift. A solid choice if the price difference matters.
Anker Nano Power Bank (10K, 30W, Built-In Cable) Budget Pick
Anker Nano 10K (A1638, 45W) – the current model
UK price at time of writing (March 2026): approx £37.99
The A1638 is where Anker took everything that made the Nano popular and improved the two things that actually mattered: output speed and cable design.
The retractable InstaCord cable
The defining feature of the A1638 is the 70cm retractable InstaCord cable. Pull it out and it adjusts to six different lengths, locking at each position. When you are done, a slight pull releases it and it retracts back into the body cleanly. In practice it is significantly more convenient than a fixed cable for travel — no snag risk in a bag, no awkward bulk when it is stored.
Anker rates the InstaCord to 20,000 bends and 20,000 pulls, which is a meaningful durability claim for a built-in cable covering well over a decade of daily use.
Charging performance
At 45W single-port output, the A1638 fast-charges modern phones at genuinely useful speed.
Real-world results from independent testing:
- iPhone 16 Pro: zero to 50 percent in 27 minutes
- iPhone 15: 52 percent in 30 minutes
- Samsung S24+: zero to 50 percent in 25 minutes
- iPad Pro (M4): zero to 50 percent in 46 minutes
Those are strong numbers for a 10,000mAh bank. The 45W output is what makes them possible.
One thing to understand about multi-port use: when you plug in two devices, each USB-C port drops to a maximum of 15W. Three devices active drops everything to 7.5W per port. Fine for earbuds and accessories. Not ideal if you want to fast-charge your phone at the same time. Charge one device at a time if speed matters to you.
What the capacity actually delivers
The 10,000mAh headline understates the efficiency losses involved. After the 35 to 45 percent loss that happens in lithium-ion conversion, you are delivering roughly 20 to 24Wh of usable energy to your devices. Anker confirms this on their own Amazon UK listing, stating the A1638 delivers approximately 5,500 to 6,500mAh of usable power to connected devices.
In practical terms, here is what that means for real devices. Battery capacities are sourced from official manufacturer specifications and Apple EU energy labels published September 2025:
Anker Nano Power Bank (10K, 45W, Retractable Cable) Best Compact Pick
| Device | Battery | Source | Est. charges — A1638 (45W) | Est. charges — A1259 (30W) |
|---|---|---|---|---|
| iPhone 17 | 3,692mAh / 13.66Wh | Apple EU energy label, Sept 2025 | 1.5 to 1.8 | 1.2 to 1.5 |
| iPhone 17 Pro Max | 5,088mAh / 18.83Wh | Apple EU energy label, Sept 2025 | 1.1 to 1.3 | 0.9 to 1.1 |
| Samsung S25 Ultra | 5,000mAh / 19.25Wh | Samsung official specs | 1.0 to 1.2 | 0.9 to 1.1 |
| Samsung S24 | 4,000mAh / 15.36Wh | Samsung official specs | 1.3 to 1.6 | 1.1 to 1.3 |
| Google Pixel 9 | 4,700mAh / 17.39Wh | Google official specs | 1.1 to 1.4 | 1.0 to 1.2 |
| iPad Air M2 | 7,538mAh / 28.65Wh | Apple official specs | 0.7 to 0.8 | 0.6 to 0.7 |
| MacBook Air M3 | 52.6Wh | Apple official specs | Emergency top-up only | Emergency top-up only |
All figures are calculated estimates. Usable output range based on Anker’s confirmed 5,500 to 6,500mAh delivery figure (Amazon UK product listing). Real results vary with ambient temperature, battery health, screen-on time, and device charging behaviour.
Can the Anker Nano 10K charge a laptop?
Anker’s own product page addresses this directly: the bank cannot sustain 45W laptop charging for long due to heat buildup and limited capacity. Emergency top-up use is possible but not reliable. If laptop charging is a priority, the Anker 737 or A1695 are the right tools for that job.
The display
The A1638 has a smart TFT colour display showing real-time battery percentage, which ports are active, and wattage output per port. This is genuinely useful information during charging — not just dots.
Pass-through charging
The A1638 supports pass-through charging. You can recharge the bank from a wall charger while simultaneously charging a device through the USB-C port. Useful when you only have one available socket.
Airline carry-on status
At approximately 36Wh, the A1638 is well within the 100Wh carry-on limit applied by most airlines. No special approval needed. It must travel in carry-on luggage, never in checked bags. Always confirm with your specific airline before flying.
Full specs (A1638)
| Spec | Detail |
|---|---|
| Capacity | 10,000mAh (approx 36Wh) |
| Max single-port output | 45W |
| USB-A output | 22.5W |
| Recharge input | 30W max |
| Ports | USB-C port, USB-A port, retractable USB-C cable |
| Cable length | 70cm retractable |
| Weight | approx 232g |
| Dimensions | 81.5 x 50.5 x 36mm |
| Display | Smart TFT colour showing battery %, ports, wattage |
| Recharge time | approx 2 hours at 30W |
| Airline carry-on | 36Wh — within 100Wh limits |
| UK price (March 2026) | approx £37.99 |
| Warranty (UK) | 18 months |
What we like about the A1638
The retractable cable is the right design. It extends further than you expect, locks cleanly at each length, and retracts without fuss. For travel this is a meaningfully better experience than a fixed cable.
It actually fits in a pocket. At 232g and 81.5 x 50.5 x 36mm, this is significantly smaller and lighter than a high-capacity laptop bank like the Anker 737 (630g). Darleene carries this in her scrub pocket during 12-hour nursing shifts and it sits comfortably without adding bulk.
The display tells you something useful. Real-time percentage, active ports, and per-port wattage. Not just LED dots.
Pass-through charging works well. One socket, phone and bank charging simultaneously. Solves a genuine travel problem.
Airline-friendly without question. 36Wh means no maths anxiety and no security conversations.
What to watch out for
Thermal throttling under sustained load. TechRadar flagged this in their testing the output can drop below 45W as the bank heats up during extended charging. This is not a defect. It is the same protective behaviour as CPU throttling under load: the bank is protecting its cells from sustained heat. In normal phone-charging use you are unlikely to notice. In warm environments or when running all three ports at once for extended periods the displayed wattage may fall below the maximum.
Not a laptop charger. Anker’s own documentation is clear on this. Emergency top-up only.
No wall charger in the box. You need a 30W USB-C wall charger to hit the two-hour recharge time. If you only have a basic adapter, budget for a GaN charger alongside the bank.
The finish marks easily. Macworld noted the housing is more prone to surface marks than some alternatives. A small pouch or sleeve helps if you keep it loose in a bag.
Real world scenarios
The commute. Phone at 40 percent leaving the house. Plug in with the retractable cable as you walk or sit on the train. At the office the phone is back above 80 percent. No cable to fish out of a bag, no knot to untangle.
The short trip. Two nights away, phone and earbuds only. The Nano 10K fits in a jacket pocket or sits in a small bag without dominating your kit. Both devices covered for the whole trip.
The hospital shift. Darleene keeps the A1638 in her scrub pocket through 12-hour shifts. Phone charged between rounds, earbuds topped up during breaks. The compact size and retractable cable make it practical in a way a larger bank would not be.
When this is not the right tool. Long-haul flight with a laptop, iPad, AirPods, and a full working day on arrival. The Anker 737 or A1695 are the right banks for that job, not this one.
How the Nano 10K fits into the Anker range
These are not competing products. They solve different problems.
| Nano 10K A1638 | Anker 737 | |
|---|---|---|
| Capacity | 36Wh | 89Wh |
| Weight | 232g | 630g |
| Best for | Phone, earbuds, everyday carry | Laptop, multi-device, travel |
| Laptop charging | Not recommended | Yes, up to 140W |
| Built-in cable | Yes, retractable 70cm | No |
| UK price (March 2026) | approx £37.99 | Higher |
If you travel with a laptop, the 737 is the right primary bank. The Nano 10K makes sense as a lightweight companion for everyday carry, or as a standalone bank for lighter travel days where the laptop stays home.
Read our full Anker 737 review ➡️
Frequently asked questions
Is the Anker Nano 10K worth it?
Yes, for the right buyer. If you want a compact phone-first power bank with fast charging, a built-in cable, and a display that actually gives you useful information, it is one of the best options at this size and price. The A1638 is the version to buy if you want the best charging speed and the retractable cable. The A1259 is the version to buy if budget is the priority.
How many times can the Anker Nano 10K charge an iPhone?
Based on Anker’s confirmed usable output of 5,500 to 6,500mAh and official battery capacities from Apple’s EU energy labels (published September 2025): the A1638 will charge an iPhone 17 approximately 1.5 to 1.8 times, and an iPhone 17 Pro Max approximately 1.1 to 1.3 times. Real results vary with temperature and battery health.
Can the Anker Nano 10K charge a laptop?
Not reliably. Anker’s own product page states the bank cannot sustain 45W laptop charging for long due to heat buildup and limited capacity. It can provide a short emergency top-up but should not be relied on for regular laptop charging. For that, look at the Anker 737 or A1695.
Is the Anker Nano 10K allowed on planes?
Yes. At approximately 36Wh, both models are well within the standard 100Wh airline carry-on limit. No special approval needed. Always travel in carry-on luggage, never in checked bags. Confirm with your specific airline before flying.
What is the difference between the Anker Nano 10K A1259 and A1638?
The A1259 is the 30W version with a fixed non-retractable cable, priced around £26 to £30. The A1638 is the current 45W version with a retractable 70cm InstaCord cable, priced around £37.99. Both are available on Amazon UK. The A1638 is the better buy for most people.
How long does the Anker Nano 10K take to recharge?
Approximately 2 hours with a 30W USB-C wall charger (A1638), or around 2 hours 15 minutes (A1259). No wall charger is included in the box with either model.
Does the Anker Nano 10K support Samsung fast charging?
The A1638’s USB-C port and retractable cable support USB PD and Samsung Fast Charging 2.0. Independent testing showed the Samsung S24+ charging from zero to 50 percent in 25 minutes.
Final verdict
The Anker Nano 10K is a well-made compact power bank that solves a real problem: keeping your phone and small devices charged without carrying something heavy or fiddly.
If budget is the deciding factor, the A1259 (30W, approx £26 to £30) does the job reliably, with a fixed cable, lighter weight, and a longer warranty.
If you want the best version, the A1638 (45W, approx £37.99) is worth the extra £10. The retractable InstaCord cable is genuinely more convenient for daily use and travel, the 45W output charges faster, and the display gives you real information while it does it.
For phone-first travel days, commutes, and everyday carry, the A1638 is one of the best options available at this size and price.
For the full range of power bank options from compact to high-capacity, see our best power banks for 2026 guide➡️
Anker Nano 10K (A1638).
The definitive 2026 review of the Anker Nano 10K (A1638). Features a 45W output, 70cm retractable InstaCord, and smart TFT display.
Product SKU: A1638
Product Brand: Anker
Product Price: Priced around £38 at time of writing
Product In-Stock: InStock
