Sorry, no idea and could be any brand. On the assumption they bought it after the car was made in 2000, it's more likely a maintainer not a tender-izer. As such, my thought is sumtin' is better than nuttin'.
Use a mirror & a smart phone and try taking pictures of other sides...especially big flat one facing battery.
You probably realize and just removed for photo but just in case your battery vent tube is disconnected.
Good luck
