Anyone used the eBay micro USB ro ligtning adapters?

Would be handy to have one or even two of these about. The official Apple ones are £15, and I might never use them to be honest.
I've seen eBay ones, unofficial of course and they are £3.50, they state unofficial, but quality.

Wondering if anyone used them? Could I damage my iPhone 5 using these?
Can someone recommend a particular one from Amazon UK ideally or eBay at a push?

I'm not bothered about it syncing, just charging. It would be handy to have in my wallet/pocket/car for using. Means I could then use a micro USB lead in the car

Cheers

No one? Just it would be handy to have a couple, but to buy 2 Apple official ones here in UK would be £30!! I may only use a few times...

No one bought any?