I'm reading that a good fully charged battery should be at 12.3 V resting. My battery has been sitting on a smart charger and maintainer and says 12V only and the charger
Car battery voltage chart — Ricks Free Auto Repair Advice Ricks Free Auto Repair Advice | Automotive Repair Tips and How-To
AGM Battery Voltage Charts: 12V, 24V Deep Cycle Battery Voltage