A battery powered battery charger?

This weeks craziest gadget is one of the craziest ideas Ive ever seen, The battery powered battery charger. Wait, what? Yes you heard right, this device uses batteries to charge other batteries. As crazy as that sounds, it might not be that bad of an idea. Heres how... (thank you to OhGizmo for explaining what i could not)The device charges up AA or AAAs batteries, not from a wall outlet, but from D batteries that you put in the other side (not included). Disposable batteries typically have a capacity of 12,000 mAh, while rechargeable AA batteries have capacities of around 2,500 mAh or less, meaning that you could potentially charge a whole gang of AA/AAA's on the road without outlets (say, when camping), so long as you brought along a few D's to power them. But the environmentalist in us thinks that carrying a bunch of smaller batteries is probably the more efficient option. Either way this product is definatly better than the solar powered flashlight.