Cygolite Hotshots run a ridiculously long time between charges in some modes. I usually run my Hotshot SL 50 in triple flash mode, which Cygolite claims is good for 36-96 hours depending on tempo setting. The zoom and steady pulse modes, which alternate between steady and flash are good for 3-10 hours.
I haven't timed these but even when I run the Hotshot on every ride, including daytime, I only charge it once a week -- usually before the low battery indicator starts.
But the Hotshot isn't as slim as the Thunderbolts and doesn't strap easily to the seat stay.
I usually clip the Hotshot onto a saddle bag loop, or to the provided seat post mount on my road bike, just below the saddle bag.