I bought this Tollcuudda Waterproof 10,000 mAh solar power bank from Aliexpress. It turns out that it cannot deliver 2.1A as claimed, nor is it really 10,000 mAh. It’s also not waterproof. Do not buy.

I bought this Aukey 20,000 mAh Dual USB and Lightning power bank from Amazon UK. I paid £21.49, but it normally seems to be available for between £20 and £23. It doesn’t have many fancy features, it’s brick shaped and heavy, but it is a solid powerbank with an impressive capacity for a good price. Recommended.

This Power Geek “Awesome” 2200 mAh power bank came from Poundland for the princely sum of £2. They do a 4000mAh version for £5 too. It’s interesting if you need to power a very low current device because it doesn’t cut the power off under low load like most power banks do, but it was unable to sustain 1 amp for the whole discharge test. For light loads like bluetooth headphones it’s good value, but look elsewhere if you need to charge a smartphone.

I bought this Juice Long Weekender Dual USB 10,050 mAh power bank from Sainsbury’s for £20. Normal retail price appears to be £30. I’m not a fan of the fingerprint magnet mirrored part of the case, but it meets the claimed specifications and seems to be of a reasonable quality. Not bad for £20 if you need something you can pick up today.