In　the　field　of　wireless　charging　technology　for　electric　vehicles,　the　charging　process　of　lithium-ion　batteries　is　typically　divided　into　two　stages:　constant-current　(CC)　charging　and　constant-voltage　(CV)　charging.　This　two-stage　charging　method　helps　protect　the　battery　and　extend　its　service　life.　This　paper　proposes　a　family　of　circuit　topology　design　schemes　that　achieve　a　smooth　transition　from　CC　to　CV　charging　stages　by　using　two　relays.　Additionally,　the　paper　derives　the　corresponding　system　efficiency　formulas　and　provides　constraints　on　device　parameters　to　ensure　that　the　charging　efficiency　remains　high　during　different　charging　stages.　The　proposed　family　of　circuit　topologies　adopt　unified　device　parameters　and　relay　control　logic,　simplifying　the　design　and　operation　process,　and　making　these　topologies　more　suitable　for　large-scale　applications.　To　verify　the　practical　performance　of　these　topologies,　the　paper　constructs　experimental　prototypes　and　conducts　tests.　The　experimental　results　show　that　the　proposed　family　of　topologies　can　stably　achieve　CC　and　CV　output,　with　smooth　transitions　between　the　two　charging　modes,　and　the　efficiency　can　be　maintained　above　89%　before　and　after　mode　switching　over　a　wide　load　range.　Furthermore,　the　mode　switching　points　of　the　proposed　family　of　topologies　are　multiples　of　two.　©　2024　by　the　authors.