You can find some "D" sized Lithium batteries also... their 3.6v but you can use two in a 2-cell maglight and change out the bulb for a 5-cell bulb... get a brighter light, longer battery life, longer storage life, and I've never had a Lithium battery leak on me... THis setup gives you an 80-90 lumen light with Mag's Xenon bulb in a resonable size package. It is expensive ($40 and change for the upgrade), not really a viable option unless you have an old 2D-cell Maglite laying around.