This Anker 16,000mAh “Portable Charger External Battery Power Bank” has a list price of £89.99 on Amazon, but it’s down to a significantly more affordable £29.99. Nice. No discount code necessary, just pop it in your basket and run (to the checkout).
Enough capacity to charge an iPad Air twice, a Samsung Galaxy S5 four times, or an iPhone 5s over seven times.
Available in black or white. Sold by AnkerDirect and fulfilled by Amazon.
(Thanks to kevinchze at HUKD)