should still work if battery is u/s when plugged into a car providing car has power[my solus pro does when pretty flat]
should never lock out but will be out of date-my solus is 13.4 and does everything i need but lacks jap content for anything except engines and gearboxes
updates are a fortune circa £7-800 for the solus pro,but iirc if in trade you pay monthly subs for it
keys can be expensive,would buy one with decent set of keys all in one go tbh