Best price: £160 | Capacity: 21,000mAh
The PowerGorilla is the size of a small tablet and ideal for the heavy user who spends their life on the move. It comes with its own mains charger with three international plugs, which can be used to power a laptop while topping up its battery – the biggest on test. There’s a huge selection of tips, including a 12V socket, but oddly no Apple kit. Charging wasn’t the quickest and for this eye-watering price, we’d expect more than one USB.