According to Dex R’s response above, he used Flex Glue Mini Clear. If you look closely at the pictures accompanying this procedure, they show a battery connector with three wires (black, white, & red). This is identical to the battery wiring connector shown for all of the replacement batteries available from Amazon.

Search Amazon for the following and you should find several choices:

Nest Hello NC5100US C1241290 Video Doorbell Wired