The SunSocket™ EnergyBar™ 250 high capacity portable battery pack from Aircraft Spruce & Specialty is powerful enough to be classified as a generator and is extremely lightweight and safe for aircraft. It utilizes lithium ion phosphate battery technology, which is stable and nonhazardous (unlike other lithium-ions). It can provide up to 30 hours of power for many USB devices, and up to six hours of power for larger electronic equipment like thermal coolers or even laptops. For more information visit www.aircraftspruce.com or call (877) 477-7823.