1.5 amps is more like the limit for RCR123s...
here's your options: I'll list rechargable, non-rechargable, 2 cell(stock) and 3 cell(with extenders) and then list approximate WATTAGE next to each configuration, wattage is going to be your biggest indicator of brightness on an incandecent LF lamps are generally a little more efficient than others, so give them the edge on brightness when comparing similar wattage setups, also take into consideration that higher Voltage bulbs from LF tend to be more efficient as well(9V lamp>3.7V lamp by a slight amount if wattage is the same, but battery configurations usually make better use of space with 3.7V lamps for extended runtimes)...
G2 without an extender on primary cells.
1A. stock P60: ~6W ~60 min
2A. P61: ~12.5W ~20 min
3A. LF ES-6: ~4W ~80 min
4A. LF SR-6: ~6W ~60 min
5A. LF HO-6: ~7.5W ~45 min
6A. LF EO-6: ~9.5W ~35 min
G2 with no extender with a 17670 rechargable.
1B. WE D26 3.7V: ~8W ~40 min
2B. G&P 3.7V: ~8W ~40 min
3B. LF HO-4: ~7W ~50 min
4B. LF EO-4: ~8.5W ~35 min
G2 with no extender and 2 of AWs RCR123 protected with high current PCB cells
1C. SF P90, G&P G90, LF SR-9: ~9W ~30 min
2C. Pathfinder P90 (oddball), WE D26 9V: ~10W ~30 min
3C. digilight 9V (non G&P version), LF ES-9: ~6.5W ~50 min
4C. LF HO-9: ~11.5W ~20 min
G2 with extender and either 3xCR123 or 2x17500 rechargables.
1D. SF P90, G&P G90, LF SR-9: ~9.5W ~60 min
2D. Pathfinder P90 (oddball), WE D26 9V: ~10.5W ~50 min
3D. digilight 9V (non G&P version), LF ES-9: ~6.5W ~80 min
4D. LF HO-9: ~12W ~40 min
*5D. LF EO-9: ~15W ~30 min
**6D. SF P91: ~19W ~20 min
*OPTION 5D IS LIKELY TO MELT STOCK LENS. DO NOT USE EO-9 WITH RCR123 SIZE CELLS, ONLY 17500S OR PRIMARIES.
** OPTION 6D WILL MELT STOCK LENS AND CAN ONLY BE USED WITH PRIMARY CELLS, 2 EXTENDERS, 2 17670s, AND LENS UPGRADE ARE REQUIRED TO RUN THE P91 ON RECHARGABLES.
There ya have it.
just choose a wattage/runtime and battery configuration that you like the balance of. Brightest isn't always best, also keep in mind that the SF P61 and P91 are floods, while most of the other lamps are more geared towards throw... An HO-9 will out-throw a P61 big time.
