Rank #9 in Best 20000mAh Power Bank: 10 Ranked by Real Charge Counts
INIU 22.5W 20,000mAh Power Bank, Pocket Size
Price and rating as shown on Amazon when we collected them. Both change.
The INIU P51-E2 sits at number nine in this guide. It is a 20,000mAh power bank at £29.99, rated 4.6 from 358 reviews, and its headline claim is "Market's Smallest" — the tiniest 20,000mAh pack on sale, measuring "just 4.5\" diagonally". The spec fields underneath that bullet tell a different story: Item Dimensions 10.4 x 7 x 2.9 centimetres, and Item Weight 370 g.
What makes this listing interesting is the one number that normally gets buried. The Battery Weight field says 320 Grams — so the cell alone accounts for roughly 86% of the pack's total mass. Compare that with the 40 g battery weight listed on the Riapow bank further up this guide, and you can see which figure is doing the work. A 20,000mAh cell that weighs 320 g is a number that hangs together with the claimed capacity; a 4.5-inch diagonal claim sits less comfortably next to a pack that is 10.4 cm long. The listing also contradicts itself on quantity: Unit Count reads "48.0 count" while Number of Items reads "1" and the box contents field lists one power bank, one cable and one manual. Everything on this page comes from the Amazon listing as published — none of it is from our own testing.
How those 358 ratings break down
An average hides its own shape. This is the spread behind the 4.6 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £29.99 |
|---|---|
| Rating | 4.6 out of 5, from 358 reviews |
| Claimed capacity | 20,000mAh (as listed) |
| Item weight vs battery weight | 370 g total, of which 320 g is the battery (as listed) |
| Dimensions | 10.4 x 7 x 2.9 cm |
| Ports | 2 x USB-C input/output plus 1 x USB-A output |
| Quantity fields | Unit Count reads 48.0 count; Number of Items reads 1 (as listed) |
| Warranty | 3-year iNiu Care, warranty type listed as Limited |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“It's a bit heavy so I just used it as my festival power bank. Useful when sleeping in a tent and haven't got anywhere to charge your phone. Lasts forever”
Verified purchase“Perfect for a couple days camping. Charged two phones up twice with juice to spare. Really portable and the charging cable doubles as a handle which is great.”
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
How many times can the INIU P51-E2 charge a phone?
The listing says it will charge an iPhone 16 four times and a Galaxy S23 three times.
How heavy is it?
The listing gives an item weight of 370 g, with 320 g of that recorded as battery weight.
Is it really the smallest 20,000mAh power bank?
The advert calls it "Market's Smallest" and cites a 4.5-inch diagonal, while the spec fields list dimensions of 10.4 x 7 x 2.9 cm.
Can I take it on a plane?
The listing says it fits into a pocket, chest bag or other small bag and can be taken on a plane.
How fast does it charge?
The bullet says 22.5W and 75% power in just 25 minutes; the spec fields do not list a charge or recharge time for the INIU P51-E2.
What is in the box?
The listing says one INIU 20,000mAh portable charger, one cable and one user manual.
Comments
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