Battery holder : Li-Ion 18650 Battery Holder (4S1P) With 2.6" long 20AWG & PCB
China 4 Cell Li-ion 3.7V 18650 Battery Holder Case Plastic Lipo Battery Holder with PC Pin - China 4 Cell Li-ion 3.7V 18650 Battery Holder, with PC Pin
M5Y1K Battery for 4-Cell Lithium-Ion Battery for Dell Inspiron, Latitude and Vostro (type M5Y1K) - Walmart.com