I have the H600w for when I need a serious headlamp, but it also works well for around camp when it is set on a low setting. But I also have the H302w flood, which is tiny and runs on CR123 batteries. I have rechargeable CR123, but I usually just throw in Energizer CR123 lithium. These are not very expensive and I can find them anywhere. The H302w has better specs than the H52 or H502. The batteries last longer, it is a smaller headlamp, and it has brighter settings.
For both headlamps I seem to be getting much longer battery life than what the specs say. I run my projected use times when going on a backpack trip and bring enough batteries for what I anticipate. But I always seem to not need the extra batteries, not needing even close to what I anticipate. Maybe it is my imagination since I have not actually timed it?
H302w:
Light Output (runtimes)
High:         H1 446 Lm (PID, approx 1.4 hr)   or    H2  245 Lm (1.6 hrs) / 100 Lm (4.1 hrs)
Medium:    M1 50 Lm (11 hrs)    or    M2   22 Lm (26 hrs) / 8.5 Lm (70 hrs)
Low:         L1   2.5 Lm (8 days)   or    L2   0.37 Lm (38 days) / 0.05 Lm (2.5 months) / 0.01 Lm (3 months)
H502w:
Light Output
High:         H1 260 Lm (0.9 hrs)   or    H2  160 Lm (1.9 hrs) / 100 Lm (3.3 hrs)
Medium:    M1 50 Lm (7.5 hrs)    or    M2   25 Lm (12 hrs) / 12 Lm (27 hrs)
Low:         L1   2.7 Lm (4 days)   or    L2   0.34 Lm (3 weeks) / 0.06 Lm (2 months) / 0.01 Lm (3 months)