tonkem
Enlightened
You need to look at the total energy in terms of watt-hrs (VxMah). A 14500 will have greater runtime than a standard Eneloop for a given lumen level.
3.7x750=2.8 w-h
1.2x2000= 2.4 w-h
(Except perhaps over a long term due to increased parasitic drain the SC52 has with 14500s)
Seems I have learned something today. My apologies to the OP for the incorrect information. I guess it seems a lower runtime to me, because I use the MAX 500 lumen output quite a bit, so the runtime will likely be much less than the 2000 mah eneloop battery, since the max brightness is only slightly brighter than the lowest of the H2 levels, so I don't use it much.
My apologies
Tonkem