TOPK Power Bank, 20W USB C Fast Charging 20000mAh Portable Charger, PD3.0 QC4.0 Battery Pack With Digital Display PowerBank Compatible with iPhone 13 Pro Max, Samsung, Huawei, iPad, and More

very heavy and coarse but very good capacity

Very good and practical power bank👍🏼

A reliable Portable charger, used it when traveling, a bit heavy but otherwise great product

Fast charging and capacity as expected. Hope it has a long life span

First of all, the capacity is advertised as 20,000mAh but that's for the internal 3.7v cells.At 5v (USB output), the 74Wh of the battery capacity would convert to 15,000mAh.In actual use, I think the capacity is a maximum of 14,000mAh based on my testing, when charging devices in USB.All manufacturers provide a capacity at 3.7v instead of 5v, so the large discrepancy (30% less) is not specific to this product.It means the power bank can charge my Huawei Tablet (5,100mAh battery) about 2.5 times, or my Samsung S10 (3,400mAh battery) about 4 times, which is still very respectable.The power bank is able to charge either of my devices quickly (PD protocol for Huawei, QC for Samsung). However, it can only do a quick charge if only one device is connected (else it's a slow charge for all connected devices). When performing a quick charge, "PD" appears in green on the display (even if it's actually the QC protocol used).When charging the power bank with a quick charger, PD also appears, and the percentage in the display blinks.The display is useful to see the remaining battery, in exact percentages (not rounded).At 470g, this device feels heavy and a bit of a brick, but then don't expect a "20,000mAh" capacity device to weight less than 450g (even if made of plastic), it's simply not possible.The build quality is very good, with a smart looking metal casing. Power bank doesn't get hot when charging devices, nor makes any buzzing noise.A short USB A to USB C cable is provided, which can be used to charge the power bank, or charge a USB C device from the power bank.Overall, this is a well made, large capacity device.

This is quoted as 20,000mAh which, if you didn't know is the mAh at cell voltage which is 3.7V, not the 5V output (that's normal for these battery packs)This relates to 74-Watt hrs.After cycling the battery from new, 4 times and doing a discharge test from fully charged to the cut-off voltage it managed 66.9-watt hrs and a Capacity of 12967mAh @ 5.1VOne of the best I have tested to date.

I purchased this alongside a usb type c cable for my iPhone and it has not disappointed it’s capable of a few solid charges from dead 4 to be exact it’s a bit on the heavy side but that’s to be expected from its capacity I do like the little screen feature that shows power banks current capacity and the face it takes usb c is a plus charging takes a while about 6-10 hours from 0 to 100% for the power bank but believe me it’s well worth its money.

Used it for charging my phone while camping, it used 3% of its battery power to charge my phone up to 25% initially. Then it turned itself off, when I held the power button down to turn it back on it showed 0% battery life and wouldn't charge anything. Despite me charging the power bank up to 100% before I left!Bitterly disappointed and will be requesting a full refund due to a faulty product.

Decent metal chassis. Anyway, 20,000 mAh/3.7V should be 14,800@5V. However it handily gives a more useful 75Wh rating on the back. After a month of light use I decided to test this and charging from an indicated zero% using a PD charger over USBC it took 81.94Wh to charge to 100%. About a 10% loss from charging, not too bad thinks I. Alas, charging to empty resulted in an output of only 53.05Wh. in other words, only about 63% of the rated capacity. Two stars as it seems solidly built, would have liked higher voltage negotiation and more than 20W output, highest I have seen is about 18W. The power level indicator drops rapidly once it gets to about 20%