12v Car Battery Backup

I have an extra 12v car battery laying around and I would like to use that as a battery backup for the Konnected system.  Do I need to have any kind of amp regulator between the battery and the konnected device or can I just wire it straight up using a 2.1mm connector like the one listed here:  https://www.cablewholesale.com/specs/30w1-00200.php?utm_source=GoogleShopping&utm_medium=cpc&utm_term=30W1-00200&utm_campaign=DC%20Male%20Power%20Plug%20to%202%20Pin%20Terminal%20(Screw%20Down)%20Adapter&gclid=CjwKCAiA98TxBRBtEiwAVRLqu_k1AG9MPpGwwCqLjDuCaU9GaNvp9hPOkdFiTlHBbgEL3dZE1aKMbRoCRVAQAvD_BwE