Three AAA direct drive light with a single 10440?

I have managed to acquire one of these under-counter LED lights that uses three AAA cells in a direct drive setup. I know it is direct drive because of the dimming that goes on as the cells discharge. Currently I am using three NiMH cells, but was wondering how a single 10440 with two dummy cells would work. Using three NiMH or primary cells the input voltage is around 4.5v, dropping down to the forward voltage of the LEDs as the light is used. Using a single 10440 with a max voltage of 4.2v would seem to me to not be a problem, but I wanted to ask if anyone else has tried this in a direct drive situation.

A typical 10440 has about 300mAh of capacity, so even though AAA alkaleaks are at the bottom end of the equation, I think that you're better off just using NiMH AAAs if you have to run one of those 3xAAA lights. Especially at the lower end of the output scale of things.

It's not worth the effort, IMO.

But have at it!

Chris