Three chemistries cover almost every household battery purchase. They look identical on the shelf and behave quite differently in a drawer, a cold garage or a camera flash.
Side by side
| Alkaline | Single-use lithium | NiMH rechargeable | |
|---|---|---|---|
| Nominal voltage | 1.5 V | 1.5 V | 1.2 V |
| Rechargeable | No | No | Yes, hundreds of cycles |
| Good in the cold | Poor | Very good | Moderate |
| Shelf life | 5 to 7 years | 10 to 15 years | 1 to 5 years depending on type |
| Leak risk if left in | High | Low | Low |
| Best for | Clocks, remotes, low drain | Smoke alarms, torches, cold or long storage | Controllers, toys, daily use |
Alkaline: cheap and cheerful, with a catch
Alkaline is the default for a reason. It is inexpensive, widely available and ideal for low-drain devices. Its weakness is that the chemistry slowly produces gas and can leak potassium hydroxide, a corrosive liquid that damages contacts and circuit boards.
Leaks are far more likely in a battery that has been fully discharged and left sitting in a device. If you store something for the season, take the cells out.
Single-use lithium: expensive but excellent
Lithium iron disulfide cells are also 1.5V, so they are drop-in replacements for alkalines in most devices. They hold their voltage under load, work at minus 20 degrees, and last many years unused.
For a smoke alarm, a bike light kept in the shed or a device that must work after a year on the shelf, they justify the price.
NiMH: the one that pays back
Modern low-self-discharge NiMH cells arrive pre-charged and hold most of it for a year. They tolerate hundreds of cycles, so four cells plus a charger can replace hundreds of alkalines over a decade.
The 1.2V label is fine for nearly everything. Devices that struggle are usually poorly designed or rely on voltage to guess remaining battery life, such as some battery gauges and older cameras.
Do the sums before buying premium cells: for a remote that drains two AA batteries a year, alkaline is cheaper. For a games controller or child's toy that eats cells monthly, NiMH wins within weeks.
Mixing is the mistake to avoid
Never mix chemistries, brands or states of charge in the same device. The strongest cell drives the weakest, which causes overheating and leakage, and it makes rechargeable sets fail early.
Keep rechargeables in matched sets, write the purchase date on them, and retire the whole set when performance drops.
The short version
- Alkaline suits low-drain devices that get used, not stored.
- Single-use lithium is worth it for cold, long storage or critical devices.
- NiMH wins on cost for anything used weekly.
- Never mix chemistries or old and new cells in one device.