Lithium are a lot safer too. They have their built in Battery Management System so you can’t over charge or drain to 0 volts. They do have a little higher voltage rating, so make sure your motor and electronics can handle it. I think they would if designed for 12 volts system.

Battery chargers aren’t much more than a good charger for a SLA. They do charge at a higher voltage. There are chargers that will handle both types of batteries too.