New Aurora/UltraFire 3xAA or 1x26650 light with XM-L LED

I wouldn’t recommend alkalines, they can’t deliver high currents for long
NiMH is far better, most brands can deliver the max current necessary for this light

I hope i haven’t violated any faux pas on this forum by posting a CPF link

This makes a good point that the holder may be the source of higher resistance so less output from the 3AA batteries.