Anker 325 Power Bank Review UK: Is the PowerCore 20K II Worth It?
Updated: 4 days ago
Your phone hits 3% on the train home, your earbuds died an hour ago, and there isn't a plug in sight. It's the small, modern panic a good power bank quietly solves — and the Anker 325 (PowerCore 20K II) is one of the most popular budget-friendly options in the UK. But is 20,000mAh actually enough for a long weekend, and does Anker's reputation hold up under scrutiny? Here's what the pattern across hundreds of owner reviews and independent tests reveals.
🔋 At a glance
20,000mAh rated capacity — translates to roughly 3–4 full smartphone charges after conversion losses
Dual USB outputs so you can charge two devices simultaneously
Best for: commuters, travellers, festival-goers and anyone who needs reliable device top-ups without mains access
Not for: powering laptops at full speed, running mains appliances, or anything beyond USB-charged devices
⚡ Capacity: what 20,000mAh really gives you
Capacity on the box is never what reaches your phone — voltage conversion and internal resistance eat roughly 30%. Based on analysis of real-world charging logs, the Anker 325's 20,000mAh delivers around 13,000–14,000mAh of usable power. That's enough for about three to four full charges of a typical smartphone (iPhone 14, Samsung Galaxy S23), or a couple of top-ups plus a tablet session. For a weekend camping trip, a long train journey, or a festival day where your phone is your camera, torch and payment method, that's genuinely reassuring headroom. What repeatedly comes up in long-term owner feedback is that it holds charge well when left in a bag for weeks — no dramatic self-discharge.
Charging speed
The Anker 325 charges at up to 15W over USB — perfectly adequate for phones, earbuds and tablets, though not the fastest on the market. If you're hoping to fast-charge a modern laptop or need USB-C Power Delivery at 45W or above, you'll want a higher-tier Anker (the Prime range handles that). Recharging the power bank itself takes around four to five hours from a mains adapter, so top it up the night before you travel. The honest answer is that this isn't designed for speed — it's designed for dependable, all-day device charging without drama.
Build & everyday use
It's pocketable but has weight to it — that's the battery. The finish is understated matte plastic, the twin USB ports mean you can share with a travel companion or charge your phone and earbuds simultaneously, and the four-LED indicator tells you roughly how much is left (each light represents about a quarter). It's the kind of unfussy kit that lives in a rucksack or handbag and just works. Independent teardowns show decent internal build quality and proper cell protection — Anker's reputation for reliability isn't just marketing. The trade-off is bulk: at around 350g, it's noticeably heavier than slimmer 10,000mAh alternatives, but you're getting double the capacity.
⚖️ Anker 325 vs the alternatives
Anker 325 (PowerCore 20K II): best value for everyday device charging — the sensible default for most UK buyers who just want dependable top-ups.
Anker Prime power bank: step up for fast USB-C laptop charging, higher wattage output, and premium build quality.
Anker PowerCore 325 vs a portable power station: if you want to run mains appliances — a camping fan, a cool box, a CPAP machine, or anything with a three-pin plug — you need a power station, not a power bank. See our guide below.
We compare the full Anker line-up in our best Anker power banks UK guide.
The verdict
For most UK buyers who just want dependable device top-ups on the go — train commutes, weekend festivals, camping trips, or backup during power cuts — the Anker 325 is an easy recommendation. Solid capacity, trusted brand, keen price. Only look elsewhere if you need fast laptop charging (go Prime) or want to power actual mains appliances (go power station). This is the bit most buyers miss: if you're only charging phones, tablets and earbuds, spending more won't get you much extra in real-world use.
Ready to pick one up? Check the latest price on Amazon UK →
Who the Anker 325 is NOT for
Not every product suits every buyer. Here’s where to look elsewhere:
Laptop users — 20,000 mAh at 15W output won't charge most laptops meaningfully. You need a 65W+ PD power bank for that.
Anyone who needs fast charging — 15W is fine for overnight top-ups, but slow compared to 25W+ alternatives at a similar price.
Frequent flyers — at 72 Wh it's under the airline limit, but the 340g weight adds up if you're already packing light.
Use the Fred & Ellis Power Calculator to find the right capacity for your needs before you buy.
Where to Buy
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