Lithium vs rechargeable batteries
Single-use lithium wins on shelf life, cold and weight; NiMH wins on cost per use. The two suit opposite usage patterns rather than competing directly.
These two are good at opposite jobs. Single-use lithium holds its charge for a decade and works in extreme cold, which makes it the cell for emergency kit and outdoor gear — but you throw it away. NiMH costs almost nothing per use and handles heavy loads well, which makes it right for anything you use regularly, but it slowly loses charge sitting unused. Pick by how the device is used, not by which cell is better: neither is.
- Verdict:
- Lithium for standby and extremes, NiMH for anything used often
Side by side
| Specification | Lithium (single-use) | Rechargeable (NiMH) |
|---|---|---|
| Nominal voltage | 1.5 V | 1.2 V |
| Rechargeable | No | Yes, 500–1000+ cycles |
| Shelf life | 10–20 years | Most of a year for low-self-discharge types |
| Cold weather | Works to about −40 °C | Reduced but usable |
| Cost per use | High | Very low |
| Weight (AA) | about 15 g | about 30 g |
Standby against duty
The deciding question is whether the device sits waiting or gets used. A head torch in a car boot wants lithium. The same head torch on a nightly dog walk wants NiMH.
Weight matters more than you would think
A lithium AA is around half the weight of a NiMH one. Across a four-cell device carried all day that is noticeable, which is why lithium dominates in hiking and photography kit.
Neither belongs in the other's charger
Single-use lithium cells must never be charged. If you mix chemistries in a household, label them — the two look similar in an AA shell and the mistake is easy to make.
Check before you swap. Batteries with similar dimensions are not always interchangeable. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.