Mark... since obtaining my 7w Goal Zero, a couple of additional units have caught my attention... ones by Powerfilm and Instapark... the one from Instapark claims 10w and ability to charge from two 5v USB ports at 2a.....I think like most any new technology, as soon as it hits the market, there is an upgrade by someone...that being said, my charging requirements are for an old flip phone that uses miniUSB, and charges with the Guide 10 battery pack, my Goal Zero unit works well...the Guide 10 pack charges additionally from a USB charger... auto or home... an additional controller charger recommended by AFLM is the Fujicell SCH 808F... it works on 120v as well as 12v dc....a lot of recommendations on the Maha brand chargers on the net... I've been happy with the 808, but use it only for charging the Sanyo Eneloop AAs... I can't recommend them enough...so far, tropical storm season has been light, so no actual use, even during Debbie... good luck on your search.. please report back...