A zero no-load power (ZNP) ac/dc adapter for electronic equipment with an embedded battery is proposed in this letter. The embedded battery is used as a signal source for the detection of load connection. Depending on the signal of load connection, an operation of the proposed ZNP ac/dc adapter is determined. When the proposed adapter is connected with a load system, the operation of the proposed adapter is the same as that of the conventional ac/dc adapter. While the proposed adapter is disconnected from the load system, the overall proposed adapter is totally turned off. Therefore, the proposed adapter can achieve ZNP consumption. To verify the validity of the proposed adapter, loss analysis and experimental results of 65 W are presented.