Okay... here's the low-down on the 'freebie' external battery's performance.

Left it on charge overnight and, 24 hours later, it took my Galaxy Note 4 battery (pretty hefty for a mobile phone battery) up from 15% to 31% charge before it was finished.

So, as expected from the meagre weight of the thing, it didn't set the world alight.

But, for an unexpected 'freebie', it's very light and portable (can sit in a trouser pocket without disturbing you too much) and it gave an extra 16% charge. And 16% would be wonderful when you otherwise haven't got any charge left at all and no means of charging handy. And it's got the logo of everyone's favourite team on it.

Overall, I wasn't expecting it with my Gold Membership and it's small and light enough and gives enough of a boost to be worth carrying around as a back-up. And they probably cost CPFC only about a quid each (bound to be made in China) but do add extra value to an arguably quite expensive membership cost. (But an expensive membership that you seem to need to have if you are serious about getting two tickets together these days).

And with the missus's one in her handbag too... that gives a total charge of 30% available. Certainly worth having. IMHO.

Cheers CPFC!