Has any of you seen these 17500 batteries? They look pretty good with the 1300 mah rating and they're in between the 14500 and the 18650 size wise.
Ultrafire 17500 1300mah 3.7v PROTECTED BUTTON TOP Protected Rechargeable Lithium Battery Li-Ion UF17500
Ultrafire 17500 1300mah 3.7v PROTECTED BUTTON TOP Protected Rechargeable Lithium Battery Li-Ion UF17500