Rechargeable vs Disposable Batteries in Camp Lights

Disposable alkaline cells are simple and sit in a drawer for a while. Rechargeable cells cost more to start and save you buying more later. Which suits your light depends mostly on how you camp, and on what the light's manual allows. Always use the battery type the maker lists.

Disposable alkaline

Alkaline cells are the usual "buy them anywhere" option. They have a catch. Alkaline batteries are prone to leaking potassium hydroxide, a caustic substance that can irritate the eyes, skin and airways.¹

You can reduce the odds.

• Store batteries in a dry place at room temperature.¹
• Take batteries out of a light you're putting away. That limits the damage from a leak.¹
• Don't mix types, or old and new, in the same light. Mixing batteries of different types or state of charge can raise the risk.¹

Overlanders should note the vehicle. Extremely high temperatures can cause batteries to rupture and leak, and the source gives a car in summer as an example.¹ A glovebox full of spares in July isn't ideal.

Rechargeable NiMH

Nickel–metal hydride (NiMH) cells come in the usual AA and AAA sizes. They lose charge sitting idle. The self-discharge is 5 to 20% on the first day and settles at around 0.5 to 4% per day at room temperature.²

Low-self-discharge versions hold charge longer but have somewhat lower capacity than otherwise equivalent NiMH cells.² Top them up before you leave. Don't count on a charge from last month.

Don't recharge disposable cells; the source says doing so can increase the risk of leakage.¹

Built-in lithium-ion packs

Many modern lights have a sealed lithium-ion pack charged over USB. These suit a trip where you can charge from the vehicle. Check the maker's manual for the charger and the cable. See also reading battery run times for how the figures work.

All lithium-ion batteries can overheat and go into thermal runaway. It can happen without warning if the battery is damaged, overheated, exposed to water, overcharged or improperly packed.³ Don't use a swollen, hot or damaged pack.

Carrying spares

Cover the terminals, so nothing metal can bridge them. The US Federal Aviation Administration lists several ways: leave batteries in their retail packaging, tape the terminals, or use a battery case.³ That advice suits a camping crate as well as a flight.

For air travel in the United States, the FAA says spare lithium batteries go in carry-on baggage only. The terminals must be protected from short circuit.³ Check with your air carrier for its specific restrictions before you fly.³

Keep spares out of the hot parts of the vehicle, and carry them away from keys, coins and tools.