At this week's International Consumer Electronics Show, Sanho to its . First is a 12-15-volt car adapter that connects a HyperJuice external battery to Apple's . While this device will let users power their computers, Sanho says it won't recharge the MacBook's own battery.

The second option from Sanho is a do-it-yourself modification kit, which lets users add two connectors--one female, one male--to their MacBook's power adapter. By doing so, you can continue to use the device normally or switch to a HyperJuice external battery if you choose. No soldering or "complex" rewiring is needed for the modification, the company said.

The new HyperJuice external MacBook batteries--including both the modification kit and car charger--will be available later in January, for prices ranging from $100 for just the car charger to $500 for the modification kit, car charger, and 222-watt-hour battery.