Best 20000mAh Power Bank: 10 Ranked by Real Charge Counts

This takes first place because it is the only 20000mAh power bank here that separates its two output figures: 87W shared across three devices, 65W to a single one. The listing claims a 14-inch MacBook Pro to 50% in under 40 minutes, and the built-in cable alone takes an iPhone 15 Pro to 58% in 30 minutes. Crucially, it is also the only one that ties a refill time to a charger you can buy — 1.5 hours on a 65W unit. For anyone shopping a power bank for laptop 20000mah use, that 65W single-port figure is the number that matters.

In use, the cable is rated for over 10,000 bends, which means it should outlast the loose cable most people lose first. The body measures 157.5 × 73.7 × 25.4 mm and weighs 439.4 g. There are three ports, a digital display, and airline approval stated in the bullet rather than the spec block. It charges from a wall charger, so it is not cordless in any sense.

That said, 439.4 g is a lot to hold while your phone charges, and the spec block contradicts itself: it lists 'Portable: No', 'Output Current: 1 Amps' and an 'Audiovox CDM3000' as a compatible phone model. None of those square with an 87W headline. If you want a bank that disappears into a jacket pocket, this is the wrong end of the list — the INIU and the VRURC are both lighter.

This 20000mAh power bank with built-in cable sits second on the strength of what it publishes. The listing states 3.9 full charges for an iPhone 15, 2.9 for a Galaxy S24 Ultra, 1.9 for an iPad Air and 1.2 for a MacBook Air — specific figures most rivals avoid. Output is 45W max, enough for 60% on an iPhone 15 in 30 minutes, and refilling runs at 40W input.

There are three ports, an LED percentage readout, and a low-current mode for AirPods, fitness trackers and watches, which most packs in this bracket skip. Certifications listed are CE, CB, FCC SDoC, NRTL, Chemical and Energy Efficiency, and the warranty runs 24 months — the joint-longest here after INIU's three years.

The catch is the charge time. The spec field says 'Battery Charge Time: 60 minutes', which reads as a full refill. The bullet says 60 minutes reaches 43%. Both cannot be true; in theory that is closer to a 2.3-hour full charge. Worth noting, too, that at 4.4 stars from 4,036 ratings it carries a 7% one-star tail — read those before buying, and skip it entirely if you need a stated weight, because the listing gives none.

UGREEN's 45W model claims a Galaxy S25 Ultra to 61% in 30 minutes and 4.2 full charges for an iPhone 16, against 3.4 for the Baseus. As a 20000mAh power bank it also feeds three devices at once: the built-in cable, a USB-C port and a USB-A port, with the LED screen showing what is left.

The built-in cable carries both input and output, and doubles as a lanyard for a bag strap — a small decision that removes the usual cable hunt. A 45W input means the pack itself refills quickly. The 468 g body measures 15.2 × 7.1 × 2.9 cm, and the warranty runs two years.

However, 468 g is the heaviest pack in this entire list, and the spec block describes it as 'Lightweight' while listing that weight two fields later. By contrast, the INIU weighs 370 g and the VRURC 310 g. Note also that no laptop charge count is given, only phone figures — if you need a MacBook Air topped up, the Anker is the one that publishes a number for it.

At £16.14 this is the cheapest power bank 20000mah buyers will find in this list, and it has the largest review base of the ten at 10,529 ratings. The claim is 4–5 full charges for an iPhone 8–16 series and 4 for a Samsung Galaxy, from a 22.5W PD/QC output that takes a phone to 50% in 30 minutes.

Ports are the selling point: four outputs and three inputs, listed as up to six. That covers USB-A, USB-C and Micro-USB, plus an 18W input compatible with an iPhone cable. The LED display reads 0–100%, and there is a low-current mode for smaller devices. Size is quoted as 11.2 × 6.95 × 2.75 cm with a weight of 310 g, and a 30-day money-back guarantee sits alongside a 24-month warranty.

Even so, the listing disagrees with itself on size. One field gives 2.7 cm thickness; another gives 10.7 cm for the same dimension. It also lists a battery weight of 148 g, the lightest battery figure here by a wide margin, which is hard to reconcile with a 310 g body holding a 20,000mAh cell. As a result, the stated 6-hour self-recharge — the slowest in this list — is one figure you can trust.

The NOBIS is the second 45W 20000mAh power bank here, and it publishes the refill figure its rivals leave out: two hours to full on a 45W input. Output matches — 45W takes a MacBook Pro 14-inch from 0 to 47% in 30 minutes, or an iPhone 15 Pro to 60%.

There are four outputs and two inputs, so four people can charge at once. The spec block lists a 376.2 g battery weight inside a 392 g body, which is the sort of breakdown most listings omit entirely. Protections are listed as auto shut-off, over-charging and short-circuit, and the display is digital with an airline-travel claim attached.

That said, this is the lowest-rated product in the list at 4.3 stars, with 10% of its 5,335 ratings at one star. There is no built-in cable, so you carry your own, and the warranty field says only 'Limited' with no period attached. If you want the fastest stated refill and do not mind a 392 g pack, £26.34 is fair; otherwise the CUKTECH is £1.39 cheaper and promises 24 months.

Charmast's 20000mAh power bank with built-in cable arrangement is the most self-contained in this list: four fixed cables (USB-C, iPhone, Micro-USB and USB-A) plus four ports, for up to six devices at once. The claim is four full iPhone 15 charges from a single top-up, which sits in the middle of the 3.4–4.5 range the rest of this list publishes.

Charging speed splits by port. The built-in USB-C and iPhone cables do 20W PD/QC; the USB-A port reaches 22.5W for compatible Android phones. The LED screen reports remaining power down to 1%, which is more useful than the four-dot indicators on cheaper packs. A travel pouch is included.

In practice, the 22.5W headline is the USB-A port alone, not the cables most people will actually use — those cap at 20W. The spec block gives no weight and no dimensions at all, so you cannot judge the pocket fit from the listing. And unlike the CUKTECH, no self-recharge time is stated anywhere.

This is the cheaper of UGREEN's two entries at £21.99, and it makes the boldest charge claim per pound: 4.5 full iPhone 15 Pro charges, or three for a Galaxy S24 Ultra, plus a '5–7 days of battery life' line. An iPhone 15 Pro reaches 60% in 30 minutes.

Output is QC 22.5W and PD 20W across two USB-A ports and one USB-C port, so three devices charge at once. There is a digital display and a built-in cable. The listing leans on a slimmer, lighter profile than earlier UGREEN models, though no weight is given to check that against.

The catch is the wattage. At 20W PD this is the lowest output here, and the '5–7 days' figure names no device, so it cannot be checked against anything. A 6-hour recharge is also the joint-slowest stated refill in this list. If you only ever charge a phone, 20W is enough; if you want a laptop, look at the 45W packs above.

The Baseus Qpow3 is the third 45W pack in this list and the only one that states charge counts next to its wattage: 3.4 full iPhone 16 charges, 1.9 for an iPad Pro, 2.4 for a Mate 60. Those are the lowest published figures of any power bank here, which is the honest trade you make for 45W two-way charging in a portable charger 20000mah class.

There are four charging routes: two supplied USB-C cables plus a USB-C port and a USB-A port. Protection covers overload, short-circuit and temperature, and double-pressing the power button toggles the low-current mode. Weight is 361 g in a 12.1 × 7.2 × 3.1 cm body, with 24 months of warranty.

However, the copy calls this pack a '2000mAh Powerbank' five separate times — a tenth of the 20,000mAh the spec field claims. That is a listing error rather than a product fault, but it is worth knowing before you buy. The warranty field also says 'Lifetime' while the text promises 24 months, and 1,210 ratings is a thin base next to Anker's 9,763.

INIU markets this as the 20000 mah power bank for iPhone owners who want it in a pocket: four full iPhone 16 charges and three for a Galaxy S23, from a body it describes as 4.5 inches diagonally. Output is 22.5W, and the listing claims 75% in 25 minutes.

There are two USB-C ports that both take input and output, plus a USB-A port, so the pack refills over USB-C and charges three devices. A digital display and a flashlight are built in, and a low-current mode covers earbuds. The warranty is three years of iNiu Care, the longest stated here, and a cable is included.

Even so, 358 ratings is the second-smallest review base in this list, so failure patterns are harder to read than Anker's or VRURC's. 'Market's smallest' is a claim with no comparison figures attached, and the spec block lists a 'Unit Count: 48.0 count' that does not correspond to one power bank. It also weighs 370 g, only 22 g under the 392 g NOBIS.