How long do batteries last?
Alkaline AA and AAA batteries keep most of their charge for about 5–10 years in storage, and lithium primary batteries for up to 20 years, when kept at room temperature in their packaging.
| Batteries (AA and AAA) | |
|---|---|
| Unopened | Alkaline: about 5–10 years. Lithium AA/AAA: up to 20 years |
| In a device | Check every 6 months; remove batteries from stored devices to prevent leaks |
| Ideal storage | Room temperature, dry, in original packaging; no need to refrigerate. |
Storage tips
- Lithium AAs handle cold far better than alkaline, which matters for winter outages.
- Low-self-discharge NiMH rechargeables plus a solar charger beat a big pile of disposables for long outages.
- Keep loose batteries in a case so terminals cannot touch metal.
Signs it has gone bad
- Batteries: white crusty residue, swelling or leakage at the terminals
- Bleach: a weak smell; it may no longer be strong enough to disinfect water
- Fuel: darker color, a sour or varnish-like smell, or separation into layers
- Canisters and cylinders: rust, dents, damaged valves or a gas smell