I use a cheap chinese light that has both a white main lamp and a two red ancillary LEDs. It has Full/Half and flashing for the white, and solid and flashing for the red, via two different buttons, and is USB chargeable so I can charge it while riding via the dynohub, which takes just over an hour from around 1/2 discharged. I never used it for more than 90 minutes on half power, but thats plenty of time to set up camp and have dinner. I really like the way one lamp can:
A. be available in case of bicycle mechanical problem at night
B. be used as auxilliary front light in case of failure
C. be used as auxilliary rear light in case of failure
At $7 it's hard to go past and I now have one for both of my two main rides.


(https://www.aliexpress.com/item/DIU-...608.0.0.zkcGTE)

edit: p.s. if buying you need to read the description carefully, there are two variants of this lamp in identical casing. One has the flashing red LEDs activated by the second button, the other has a movement sensor mode for the main lamp, and no red LEDs.