Alternator question in Other Vehicles Posted February 1, 2012 · Report reply I am replacing the alternator in my 2006 Grand Caravan. There are two options a 138amp and a 160amp. From the factory the Cargo Van style was the only one with the option for a 160amp. This came in a package with a 600amp battery. My current battery is 700amp and was going to get the 160amp alternator, but was unsure if there is any downside to doing so. Both alternators cost the same and mount the same. I don't know if I really need 160amp, but the voice in my head says bigger is better might as well. Any thoughts?