Rank #6 in Best 20000mAh Power Bank: 10 Ranked by Real Charge Counts
Charmast 22.5W 20,000mAh Power Bank, 4 Cables
Price and rating as shown on Amazon when we collected them. Both change.
The Charmast C2065 is number 6 in this guide. It is a 20,000mAh lithium polymer power bank with four cables built into the case (USB-C, iPhone, micro-USB and USB-A) plus four more ports, selling at £22.79 with 4.4 stars from 4,933 ratings. In a list where almost no two 20,000mAh banks agree on anything, Charmast's numbers sit in the middle of the range — and one of them does not survive contact with another from the same listing.
The advert claims a 22.5W maximum output and 20W PD/QC over the built-in cables. The same spec block also lists 5 volts and 3 amps, and 5 × 3 comes to 15W, not 22.5W. On capacity, the claim is "up to 4 times" for an iPhone 15 — better than the 3.4 charges claimed by the Baseus further down this guide, and well short of the 7 claimed by the Riapow. The rating count is 4,933, while the breakdown of scores supplied with the listing covers only 100 reviews. Everything on this page is taken from the Amazon listing; we have not tested the bank ourselves.
How those 4,933 ratings break down
An average hides its own shape. This is the spread behind the 4.4 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £22.79 |
|---|---|
| Rating | 4.4 out of 5, from 4,933 ratings |
| Claimed capacity | 20,000mAh lithium polymer |
| Claimed output | 22.5W max — the same spec block lists 5 volts and 3 amps, which multiply to 15W |
| Claimed full charges | "up to 4 times" for an iPhone 15 |
| Batteries (as listed) | 2 lithium polymer batteries required. (included) |
| Ports (as listed) | "Number of Ports: 6", while the connector field lists 4 built-in cables plus 4 ports |
| Score breakdown (as supplied) | 74 of the 100 reviews shown are 5-star; 7 are 1-star |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“Best power bank I've ever had. Charged my phone from almost dead 5 times over the weekend festival and my vape a couple of times too. I have a power bank from a few years ago that cost me over £30 that charged my phone and vape once. This is a great price and really handy with all the different wires you need. Would 100% recommend”
Verified purchase“Love this, I was sceptical (always am with gadgets) but it's brilliant, I have just been away and it was been so handy! It takes awhile to charge the actual bank so I leave it on over night and its full by morning. But it charges your phone do quick! Faster than the mains. It kept me and my sister going all holiday. Say it was on 80 % it recharged mine and my sister from 20% to 100% and probably still had another 30-40% left. Highly recommend. It's a little bulky and heavier then say an apple one but less then half the price of an apple one and if you need for holidays and not every day it's brilliant but I only say that because I have a small bag but if you take a normal size bag it won't be a problem.”
What it is up against
The rivals it was ranked against in Best 20000mAh Power Bank: 10 Ranked by Real Charge Counts.
Questions people ask
Does the Charmast C2065 really output 22.5W?
The listing says the USB-A port delivers up to 22.5W and that the built-in USB-C and iPhone cables support 20W PD/QC. Its own spec block lists 5 volts and 3 amps, which multiply to 15W. Both figures appear in the same advert.
How many times will it charge a phone?
The Charmast listing says the 20,000mAh capacity is enough to fully charge an iPhone 15 up to 4 times.
How many devices can it charge at once?
The bullet claims up to 6 devices at once from 4 built-in cables and 4 extra ports. The 'Number of Ports' field says 6, while the connector field lists 4 cables plus 4 ports.
What comes in the box?
Portable charger, travel pouch and user manual.
Does it show the exact battery percentage?
Yes. The listing says an LED screen shows remaining power down to 1%.
How many battery cells does it contain?
The spec field says 2 lithium polymer batteries required, and states they are included.
Comments
Reader comments are not checked against the manufacturer's claims above.
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