Mobile power supply with series connection design

The invention discloses a mobile power supply with a series connection design, which is applied to providing a discharge voltage to charge an electronic product, and includes a plurality of rechargeable batteries and a voltage regulation circuit. The batteries are mutually serially connected end to end between a first battery end and a second battery end. The voltage regulation circuit is electrically connected with the first battery end and a second battery end for receiving the voltage difference between the first battery end and the second battery end, and providing voltage to the electronic product after reducing the voltage to be the discharge voltage. Through serially connecting the batteries and combining with the voltage regulation circuit to perform voltage reduction output, the current load and the risk in use when charging can be reduced, and the better energy utilization rate can be obtained.