Post#4 » Tue Jun 16, 2015 9:32 pm
If you have a diesel, then you don't need the 80A or higher alternator. If you use a winch regularly, then okay, maybe you need it. If you are using the stereo, A/C, lights, and fan at the same time, even the 55A alternator should handle this. A gasoline engine puts more load on the system - about 2-10A depending on speed and # cylinders.
I used my 80A alternator with a refrigerator, headlights, fan, and various USB devices all day for 9 days in Death Valley. It was more than enough in my diesel.
Is it worth it? If you need to replace your alternator, this is an easy upgrade. Do you need it? I can't say, but usually no. A refrigerator could take a lot of power, depending on the model... so try to add up all of your power usage and reduce the alternator maximum load to 70% of it's rated power (or less).
Good luck with it!
"The way you think is the way you live"