In the States Sanho has introduced the "HyperMac" range, external MacBook battery packs that work with all Apple MacBooks including Pro and Air models.
Available in 4 different capacities of 60Wh, 100Wh, 150Wh and 222Wh (compared to MacBook Air's 37Wh internal battery), the external battery is capable of powering the MacBook for up to 32 hours.
HyperMac charging cables are spliced with the original Apple MagSafe connectors - so not only does HyperMac power the MacBook, but it charges the internal battery as well.
The batteries also come with a USB power port to charge any USB device individually or simultaneously with the MacBook.
With a 4-stage lighted LED indicator, the aluminium batteries will be shipping in the States this month, priced from $199.99 to $499.95.