It is normal for the DC voltage to drop, but it has to be no more than 2%. Anything higher than that and there is an issue. If your inverter has no AC output or is too low, look at the DC voltage. The voltage has t. A lot of problems with inverters can be traced back to its power supply, the battery. There are many types of issues that can come up, and almost all of them can result in faulty AC outp. Inverters have a limited load capacity. Once you reach that point, the system will no longer be able to function. It will produce all kinds of error messages and may no longer have any AC out. If you are sure the inverter is not overloaded and the power supply is sufficient, the load could be the problem. If the appliance or device is damaged, you will not see any o. The thicker and shorter the wire, the lower the voltage drop. The longer and thinner the wire, the higher the drop. Inverters come with their own wire so you do not have to second g.