Look at
The Light Site for runtime graphs that Roy made.
Mr. Tead Bear's version chart:
From tests I have done & from what I have read I would say:
LS1 rev2 (current selling & is 400mA) is 50% brighter than the LS1 rev1 with the original electronics.
The LS2 is stated to be 50% brighter than the LS1 rev2 (both run at 400mA).
LS3 is tough to say, it will be brighter (by at least 50% IMO) than the LS2 but the beam will be more diffused. It will run at 2 watts with 1x123 and have an optional 2x123 pack that will drive the LS3 at 3 watts. We will know more about the LS3 when it goes into production.
Runtimes:
Original LS rev1 (300mA):
1x123 battery -
2.5 to 3 hours & gradually dimming throughout before dropping into "moon-mode"
LS1 rev1 hybrids & rev2 (400mA): (in my tests)
1x123 & 2AA 1600mAh NiMH batteries -
2.5 hours at very near constant brightness & then drops into "moon-mode".
(note: There was a limited run of 500mA LS1 rev1 hybrids made and were about 15~20% brighter on average but runtimes were cut in half.)
LS2:
Arc's stated runtime is 1.5 hours.
My guess is closer to 2.5 hours since it's running at 400mA, just like the LS1 rev2.
LS3:
Arc's stated runtime is 1 hour on both the 1x123 & 2x123 packs.