Amazon.com: 18650 Battery Case Holder, 5 Pack 3 Slots x 3.7V DIY Battery Storage Box, in Parallel Black Plastic Batteries Case with Pin for Soldering 3 x 18650, by Ltvystore : Electronics
5 Pcs 18650 Lithium Ion Cell Triple Battery Holder Bracket for DIY Battery Pack - Walmart.com
Battery holder: Li-Ion 18650 Battery Holder (1S3P) With 2.6" long 20AWG & PCB