An AGM battery is very robust and used for many static and mobile applications, such as mobility scooters. it depends how much battery power you need.
Heavy current applications ten to use a higher volt system to account for voltage drop when high currents are drawn. AGM and lithium-based batteries are both deep-cycle batteries, same as an RV battery.
Batteries should never be discharged completely so the rated capacity isn’t available for use. A deep-cycle battery should only be discharged between 50% to 80%, only that percentage of the total capacity is available for useful power.
When higher currents are drawn the battery capacity reduces significantly, so the amps vs hours relationship isn’t linear at all.