You don't want your batteries to die when they're in your most trusted items. Lithium batteries are the future. They have a shelf life for decades, and operate better in extreme temperatures. The Energizer Ultimate Lithium AA Batteries is the best AA you can buy in our opinion.
Energizer Ultimate Lithium AA Batteries, 12 Count
WHERE TO BUY
Bottom line: The hardiest, longest-lasting AA battery you can buy. You'll want these in your flashlights, headlamps, and emergency radio. They also last the longest in storage.
No. of units recommended: You can't have too many.
Be aware: Lithium batteries have a stronger charge than many traditional batteries, and can actually damage some equipment. Check info from manufacturers to see compatibility, especially headlamps.