e.g.: https://www.ebay.com/itm/4-pcs-60mAh-3-6V-Ni-CD-Rechargeable-Battery-Button-Cell-with-Tab-Green-/401159712873?hash=item5d66fb7069
or just go to your local dollar store and pick up a 3.6V portable phone battery; it'll be a little larger but last longer. e.g.: https://www.ebay.com/itm/Replacement-Home-Phone-Battery-Ni-MH-AAA-300mAh-with-universal-Connector-3-6V/352134685746?epid=2163009360&hash=item51fcdce432:g:qwMAAOSww5JZhB1K m ----- Original Message ----- From: Paul Sussman To: m100@lists.bitchin100.com Sent: Friday, March 16, 2018 6:53 AM Subject: [M100] Model 100 Backup Battery Replacement Can anyone please recommend a source for the correct internal backup battery for the M100? I want to be sure I purchase the correct one. Thanks, Paul Paul