Why is the charging cable for my SolarSaga 80 so short?

The built-in charging cable for the SolarSaga 80 is 3 ft long. There is a 6.5 ft extension cable inside the side pocket of the Carrying Case to extend the overall charging cable close to 10 ft. The female port of the extension cable is for connecting to the male plug of the 3 ft built-in cable. There are two types of plugs at the other end of the extension cable. The original 8mm male plug (8020 thick pin) is for Explorer 2000 Pro/1000 Pro and 1500. The attached 8mm male plug (7909 thin pin) is for smaller power stations.