If you use alkaline batteries, remove them from the flashlight if it is left unused for a long time, otherwise they will leak and cause problems. Keep them near the flashlight so you can find them easily. Try sticking the batteries to the flashlight cylinder.
Pro tip: The best performing flashlights are built specifically to use lithium-ion batteries or have non-removable rechargeable batteries, which are of no use if the power goes out for a long time. Rechargeable nickel-metal hydride (NiMH) AA batteries maintain their performance better over the life of the battery, while alkaline batteries degrade more as they discharge, so buy some Panasonic Eneloops for $43. They’re better for the environment, but if they run out, you can still use regular AA alkaline batteries.
You may prefer to keep a headlamp on hand. The Black Diamond Astro 300 for $20 runs on three easy-to-find AAA batteries and has three brightness settings, the brightest of which gives 300 lumens. That’s more than powerful enough for outdoor tasks, while on the lowest setting you can get 140 hours of runtime for general indoor tasks.
Coleman discontinued our previous favorite pick, the Divide+ Push Lantern, so the Coleman 4D LED Camp Lantern for $22 is the next best choice for not many coins. Flashlights perform poorly when you need to illuminate an entire room or when you need your hands free for a task. This basic lantern offers a single setting of 54 lumens, with a run time of 175 hours on four D-cell batteries. That sounds like a lot, but next to other full-size battery-powered lanterns like the Coleman Twin LED lantern that uses eight D-cells, it’s economical. Fifty-four lumens isn’t what I’d call bright, but it’s plenty bright enough for most tasks, even reading, while extending battery life.
If you want to conserve batteries or simply prefer hanging out by the soft flickering of candlelight, keep a spare candle or two for emergencies. The Coghlan’s 36-Hour Survival Candle for $15 has three fuses that last 12 hours each. Keep a lighter or some matches nearby.
A water purifier
Most of the time, your water supply will work even if the power goes out. But major natural disasters can turn off or damage the water, and you can end up with contaminated water. The LifeStraw Go Series Water Purification Bottle for $45 marries the straw component of the LifeStraw personal water filter with a BPA-free plastic bottle to filter 99.99 percent of bacteria present in water for up to 26 gallons of water. The original bottleless straw is still a good backup option for $17, and filters up to 1,000 gallons.
Another option is the Katadyn Steripen Adventurer for $120, which purifies using ultraviolet light. Dip it into your water and stir. It doesn’t filter out sediment, but it’s small, lightweight, and runs on replaceable CR123 batteries. You can also try it Katadyn Micropur tablets for $16. They are cheap and easy to store. Drop them in water and wait a moment. The taste isn’t great, but in my experience those aren’t water treatment tablets or drops.