1. Alkaline: cheap and everywhere
Fine for low-power things like clocks, TV remotes and toys. They cost less, but can leak if left in a device for years.
2. Lithium: for power-hungry and outdoor devices
Lithium AAs last much longer in cameras, smoke alarms and battery cameras, keep working in freezing cold and are lighter.
3. Longer on the shelf
Lithium AAs keep their charge for up to 20 years in a drawer, about twice as long as alkaline.
4. Don’t mix them
Use one type in a device at a time. Some devices, like a few security cameras, ask for lithium only. Check the manual.