I am looking for a light that I will carry solely as a backup light when on camping trips. Since it will not be used often/if at all, it needs to be lightweight. I would also like to have at least a high/low mode.
My smallest 1xAA light is a L3 Illuminations L10, with a Nichia 219 LED (great tint!). It was $20 when I got it a year or two ago. I think they still make them, as well as a clicky version. Mine is a twisty. 4 modes, from moonlight to about 120 lumens. Very small, not much larger than a battery.
Klarus P1A/Jetbeam BA10, Thrunite T10, Fenix E12, Olight S15. All of these are solid 1xAA torches fitting your requirements. All of them are cheap since they’re not on the bleeding edge of technology, too.
If you get the S15R already mentioned, take note that its dock will ONLY charge 14500’s. You can’t charge NiMHs on it, you need a separate charger.