The smaller battery is the way to go. My Teres turntable was DC powered just like this, with a charger on a relay to automatically disconnect it from AC while playing. It is better that the charger be disconnected. The difference is slight, but there.
Mine was an ordinary lead acid motorcycle battery, but that was decades ago. Today I would look for Li-Ion, ideally one small enough to fit right into the unit.
Mine was an ordinary lead acid motorcycle battery, but that was decades ago. Today I would look for Li-Ion, ideally one small enough to fit right into the unit.