QuickerTek promises extended MacBook Air battery life for $350!!!
I can’t attest to QuickerTek products, but they’ve announced a new external battery charger that promises eight to twelve extra hours of battery life giving your MBA up to 18 hours of battery life. That sounds fine and dandy, but that extra juice comes at a premium.
The external battery/charger costs $350, but you’re also going to need a modified 45W MagSafe charger that costs an extra $100. Or you can send in your existing MagSafe and have it modified for $25.
The Li-ion polymer battery weighs 1.2 lb and is good for 1000 charging cycles.
Product Page (The page doesn’t reflect the new charger)