I am pretty much new with this adapter thing. I bought an adapter today with a 9 V rechargable battery. I tried my multimeter between the output and found something interesting. The output voltage is 5 volts on the 9V port. But when I am connecting the battery and turning the adapter on the voltage between them is 9V. What is wrong with my charger? I am using a DD Shager charger. Can anyone help?