The MB-D16 Multi Battery Power Pack can be powered either by six AA batteries (Alkaline or Ni-MH or Lithium), or EN-EL15 rechargeable Li-ion batteries. To use the MB-D16 with AA batteries, use the MS-D16 AA Battery Holder. When using EN-EL15 batteries to power the MB-D16, use the MS-D16EN Battery Holder.