Try the battery in the right hand expansion bay with the machine first running on AC also, and again ignore the status icon and just pull AC power to see if the Lombard switches over to battery power. It is probably best to have charged up the PRAM battery for 48 hours before the switchover test.

The two sets of battery contacts inside the laptop are quite rugged but worth an inspection by flashlight to check for crap caught on those gold plated blade contacts. It is normal on both the Lombard and Pismo to have those little square rubber bumper travel stop blocks to be of different heights (higher on the left). If you are into exploratory surgery there is a 5A SMT fuse F1 to check on the Lombard near the left bay battery connector on the top side of the PC board.