Originally Posted by n4zou

P7 flashlights are not available for use with AA batteries. DX has a pair of 18650 Lithium rechargeable Battery's for $10.
http://www.dealextreme.com/details.dx/sku.5790
and a fully automatic charger for $8.80.
http://www.dealextreme.com/details.dx/sku.6105
You could power a P7 flashlight for 2 hours running in high mode swapping out batteries only once. Running in low mode the flashlight will operate 8+ hours on a single Lithium battery or 4+ hours on medium mode. These two batteries would allow you to run all night in medium mode swapping out battery's once.