This is the light I currently use on my RR2. It runs for around 12 hours if I keep it on the lowest setting. Even the lowest setting makes me a bit nervous to use at night because it's insanely bright. Like, people think you're a cop car spotlight lol. It's also a charger and can be charged via USB-C.
I usually take it off the bike and use it as a standard flashlight when I walk my dog at night too. I highly recommend this light.