Question: 4 d batteries = how many volts?
Answer: Most AAA, AA, C and D batteries are around 1.5 volts. Imagine the batteries shown in the diagram are rated at 1.5 volts and 500 milliamp-hours. The four batteries in parallel arrangement will produce 1.5 volts at 2,000 milliamp-hours. The four batteries arranged in a series will produce 6 volts at 500 milliamp-hours.