I have looked at some cheap car USB power supplies. Griffin: http://mm0hai.net/blog/2012/09/30/Griffin-USB-Car-Charger.html http://mm0hai.net/blog/2012/09/30/G

I have looked at some cheap car USB power supplies. Griffin: http://mm0hai.net/blog/2012/09/30/Griffin-USB-Car-Charger.html http://mm0hai.net/blog/2012/09/30/Griffin-USB-Car-Charger.ht... Unbranded, common on ebay. http://mm0hai.net/blog/2012/08/01/Message-to-an-ebay-seller.html http://mm0hai.net/blog/2012/08/01/Message-to-an-ebay-seller.... They were both awful. I would be interested to know about a known good one.