Do RTG's need to be big, heavy and require large amounts of plutonium? I recall reading about plutonium pacemakers. Depending on power needs, could something sm

Do RTG's need to be big, heavy and require large amounts of plutonium? I recall reading about plutonium pacemakers. Depending on power needs, could something smaller like this be used as a trickle charge to power limited essential systems ongoing or for bursts of access? https://www.orau.org/ptp/collection/Miscellaneous/pacemaker.htm https://www.orau.org/ptp/collection/Miscellaneous/pacemaker....