The power bank is a 2600mAh enough to use as a phone backup but won't be running a laptop off of it that's for sure. Got mine today so they are still available in store. I suggest you go down make up a story about you lost the voucher and give them your details as you'd be on their system when they look you up. I gave them my voucher but they still asked for my details so waste of a time having a voucher then.