I don't blame you. I never charge from my computer--I've seen too many charging accidents, melting batteries, shorts--not worth it.
Get a new set of chargers--a wall adapter and an USB--if money is no object. It's always a good idea to have a backup. Those things do fail. And you don't want to be without a charger.
Was about to place another order tonight, didn't even think about a back up charger till now but good idea! Might as well get a Spinner while I'm at it... and a pro tank. Money is an object but hey I'll break even someday even if it's not till 2014.