I was browsing Welch Allyn's web site and downloaded the "Wire Terminal Lamps Types" PDF from this page: http://www.walamp.com/tech.asp
They have a 2.4 V 1.10 A bulb # 01121 generating 2.30 MSCP = 28 Lumen that should be driveable nicely for 1.5 hours in a Minimag with NiMh's.
I don't have a Brinkmann 3AA, but I assume that it uses the same form factor bulb. If so, bulb # 01144 at 3.7 V draws 1.6 A and generates 8.40 MSCP or 104 Lumens. NiMh's should drive this for almost an hour, but the risk exists that voltage could drop to 3.4V or 3.5V at this amperage.
The less aggressive could use bulb # 01143 at 3.7 V which draws 1.02 A and generates 5.10 MSCP or 63 lumens. A good alternative might be bulb # 01114 rated at 3.6V drawing 1.12 A generating 5.0 MSCP = 62 Lumens.
They have a 2.4 V 1.10 A bulb # 01121 generating 2.30 MSCP = 28 Lumen that should be driveable nicely for 1.5 hours in a Minimag with NiMh's.
I don't have a Brinkmann 3AA, but I assume that it uses the same form factor bulb. If so, bulb # 01144 at 3.7 V draws 1.6 A and generates 8.40 MSCP or 104 Lumens. NiMh's should drive this for almost an hour, but the risk exists that voltage could drop to 3.4V or 3.5V at this amperage.
The less aggressive could use bulb # 01143 at 3.7 V which draws 1.02 A and generates 5.10 MSCP or 63 lumens. A good alternative might be bulb # 01114 rated at 3.6V drawing 1.12 A generating 5.0 MSCP = 62 Lumens.