What do you get the person who has everything? If they have a smartphone, perhaps this useful wallet.

Mighty Power Wallet does exactly what you suspect it might: it doubles as a back-up battery.

The slim leather wallet hides a rechargeable battery that will power up the average smartphone one and a half times.

It’s not easy to tell that this wallet is packing some extras. The 3000mAh battery is tucked neatly away and doesn’t take over too much precious space inside the wallet.

It comes with both lightning and micro USB connectors too.

It's arguably more convenient than most external batteries because it is more likely to be on your person – just remember to charge it. Firebox. com