· Arc-Lithium: Industry's most advanced battery technology· Keep-Cool Cell Technology· The patented power management system protects the battery pack from the most harmful elements a battery can face from overheating to over-discharging· Weather-resistant construction. This Lithium-Ion battery pack will provide optimal performance in temperatures between 32°F (0°C) and 104°F (40°C)· Integrated fuel gauge so you know how much power is left