Efficient LEDS's and Lenses ??

I use a flashlight at work, its on about 2 minutes at a time several times a day.

Recently bought a Maglite Pro. It has good light output, but goes through about 4 alkaline batteries per week. I switched to 2000mah eneloops, its bad, almost unusable. Have to recharge before the day ends.
I tested the current draw of the Maglite Pro, its 1.75 amps, which I guess explains the short battery life.

I tested my old Maglite Multi Mode flashlight. Its current draw on the high setting is .250 amps. Although it does not have as much light output, its still decent for my purposes. Theoretically, the eneloops should last about 8 hours. I'm going to try it this week.

I also tested a Coast G25, on high setting, it draws 1.7 amps, on low it draws .250 amps. For the amount of current it draws on low, its somewhat brighter than the Maglite Multi Mode that draw the same amount of current.

The Coast has a different lens, like a magnifying lens that maybe makes it seem brighter for the same current draw.

Question is, for a given amount of battery current draw, lets say .250 amps, is there any guideline on what would be the brightest led/lens combination aa flashlight?

Thanks.

Hello Syga and welcome to CPF.

On the basis of what you've indicated with your past usage and preferences it sounds like you are illuminating a smaller area relatively close in, as opposed to say a wider area or far away objects. If that is the case, it sounds like you might be better served by a light with an TIR optic that collimates the beam evenly to a defined area, over a reflector that concentrates the the beam to a tight hot-spot with spill. If you don't need the spill for illuminating a wider area, it's essentially wasted, and the tight hot-spot from a reflector or zoom-type lens can also be overly intense and uncomfortable to use.

Since you also seem to indicate a preference for AA cells, something like the Olight S2A is an example candidate. It uses a TIR, and with 2xAA batteries and multi-levels you should get reasonable runtimes. The "recommend a light" thread would be a good place to ask about similar candidates.

Another option for run time would be to consider changing battery types to lithium rechargeables. That option opens up the world of convenient recharging cradles where you can simply plop the light at the end of the day so that it's charged and ready to go the next day.